JPS6037659B2 - multi-channel communication equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-channel communication device capable of operating on a plurality of predetermined separate channel frequencies, and more particularly to a multi-channel communication device capable of operating on a plurality of predetermined separate channel frequencies. or to a multichannel communication device having an automatically selecting step-scan electronic channel selection machine.

The most common means of step-wise tuning a multi-channel communication device to a plurality of separate channel frequencies is to use a multi-position rotary switch having a different mechanical position for each channel to be selected. .

Generally, known mechanical switches of this type are used with a plurality of different crystal channel elements so that the crystal elements can be selectively actuated depending on the position of the multi-position mechanical switch. This type of multi-position mechanical switch is commonly used in television receivers and citizen bands (
CB) Used as a transceiver tuning mechanism. Some known communication devices include a receiver that continuously manually or automatically tunes over the entire frequency band and terminates the frequency sweep when the desired frequency of the transmitted signal is tuned.

This type of automatic continuous tuning operation is itself inadequate for tuning the receiver to a predetermined channel. This is because such known circuits cannot tune the receiver to the desired channel if there is no signal transmission on the intended channel. Moreover, such continuous tuning is impractical or even undesirable when the communication device incorporates a transmitter that is required to operate only at a plurality of predetermined, highly stabilized, separate channel frequencies. Car telephone systems for automobiles also use wireless radio equipment that continuously scans a plurality of separate channel frequencies by sequentially tuning a receiver to each of the plurality of separate channel frequencies. However, these scanning devices only scan in one direction and are generally fully automatic and cannot perform manual scanning. Furthermore, the electronic part of the car telephone system in an automobile basically detects an empty channel, and does not detect the presence or absence of transmission on a priority channel and generate an audible signal in response. Such standard car telephone equipment therefore cannot tune the radio to a desired scheduled channel. One of each separate channel of a plurality of stable frequencies is scheduled using a mechanical multi-position switch.
In the case of channel selection, the channel to which the communication device is tuned upon re-powering the communication device is the channel last selected by the mechanical multi-position switch.

Automatically tuning a communication device to a single call channel whenever power is reapplied to the communication device cannot be accomplished with a slave switch. Typically, mechanical multi-position switches cannot be reset to a particular channel when repowering a communication device, and such functionality is therefore accomplished without the use of an expensive drive mechanism to rotate the mechanical multi-position switch. I can't.・In general, electronic tuning devices have a mechanical multi-position switch channel memory function, but in such conventional devices, the operator of the communication device has a previous channel memory function or when the communication device is re-energized. It is not possible to select the reset function of the call channel to which the device initially tunes. Automatic scanning and tuning devices for communication devices have already been proposed.

However, these auto-scan and tune devices typically hold tune to one of a plurality of scheduled channels, then continue to tune other channels until the auto-scan mode is terminated or the signal on the held channel is terminated. Unable to scan. In general, known devices of this type do not provide any means for the operator to maintain automatic scanning, so that if a signal is received on an undesired channel of the plurality of channels, automatic scanning must be manually interrupted. I am trying to disable it. Also, known communication devices that are capable of manual tuning and that include a transmitter are generally not provided with a device that reliably prevents the channel frequency of another transmitter from being selected during the transmission of a signal by the transmitter.

This is why in conventional systems, the transmitter channel frequency cannot be changed during transmission by a manual tuning control. Such operation is undesirable and may result in unintentionally transmitting a signal to a selected channel, or to the transmission of large voltage transients on the transmitter, or outside the permissible frequency range for any of the operating channels on which the communication device may operate. It becomes possible to transmit transient frequencies of Further, prior art devices do not provide any means to prevent manual changes in the frequency of the transmitter while the transmitter is transmitting a signal. SUMMARY OF THE INVENTION It is an object of the present invention to provide a multi-channel communication device having a scanning electronic channel selection switch.

Another object of the invention is to have two manually operated channel tuning controllers, one manual tuning controller mounted on the exterior of the communications device and the other manual tuning controller fully mounted on the exterior of the communications device. It is an object of the present invention to provide a multi-channel communication device that can be located at widely separated remote locations.

It is another object of the present invention to provide a multi-channel communication device which sequentially scans a plurality of priority channels and generates an audible signal relating to a received signal on a non-priority channel if transmission on a priority channel is not detected. There is something to do.

Still another object of the present invention is to provide a transmitter that can be manually tuned to a plurality of different channel frequencies, so that even a manual tuning device cannot change the channel frequency of the transmitter while transmitting a signal by the transmitter. The purpose of this invention is to provide a multi-channel communication device.

Yet another object of the present invention is to provide a multi-channel communication device that automatically tunes to one of a plurality of scheduled channels when power is applied, regardless of the last channel to which it was tuned. be.

In accordance with the present invention, a multi-channel communication device capable of operating at a plurality of predetermined separate channel frequencies selectively generates one of a plurality of predetermined separate channel signals in response to a control signal. A signal generator is provided to

Each of these channel signals has a different frequency such that the selectively generated one channel signal determines the operating frequency of the communication device. The visual display device also provides an indication identifying the operating channel frequency of the communication device. A first switch device is further provided for manually tuning the multi-channel communication device. The first switch device is provided with a manual actuation capable of assuming at least first and second mechanical positions. The first switch device generates an upward scan control signal when the manual operator is in a first position and generates a downward scan control signal when the manual operator is in a second position;
or the second position, the enable control signal is generated. A signal generating device is responsive to receiving these control signals from the first switching device for sequentially and selectively generating each of the different channel signals at each separate step of the first predetermined sequence. The channel signal is responsive to the presence or absence of both the enable and upscan control signals. The signal generator also selectively sequentially selects each of the separate channel signals as a single channel signal responsive to the presence or absence of both the operable and downscan control signals at each separate step of the second predetermined sequence. generate. These upper and lower scan control signals
and selecting one of the second sequences and activating the signal generator by the enable control signal to selectively generate the other of the predetermined channel signals as a one channel signal. With this configuration, any channel signal can be selected as desired. The reason is that any one of the two separate channel scanning sequences for the signal generator can be selected by means of a single channel signal selectively generated by a single actuator. According to the present invention, one of the above-mentioned switch devices can be provided on the outer shell of the multi-channel communication device, and the other switch device can be provided at a location away from the external dust.

This arrangement allows the operator of the multi-channel communication device to tune the device from a remote location if he or she is unable to reach the switch device mounted on the casing of the communication device. Further, according to the present invention, the microphone of the transmitter is provided with a channel selection switch, thereby making it possible to effectively select a channel before transmitting. Further, the present invention allows the receiver to continuously scan a plurality of scheduled priority communication channels while receiving non-priority communications and searching for transmissions of any priority communications. When a priority communication is received, scanning of other channels is inhibited, an audible signal is generated in response to the priority channel signal, and an audible signal related to a non-priority channel signal can be blocked. It also prevents manual tuning of the transmitter when it is activated.

This ensures that the transmitter's channel frequency cannot change while the transmitter is transmitting a signal. In this case the transmitter also disables its automatic channel tuning. Further, in accordance with the present invention, after resetting the channel to which the multichannel communication device is tuned and after initially supplying operating power to the communication device, the channel to which the multichannel communication device is tuned is always preselected, regardless of the channel to which it was previously tuned. You can tune into the channel first.

It is also possible for the operator to select a preselected tuning as described above, or for the communication device to remember a previously tuned channel and return to this channel when operating power is supplied to the communication device. In a preferred embodiment of the invention, the tuning of the multi-channel communication system is made dependent on the count of a counter that controls the programmable frequency division of a frequency divider provided in the phase-locked loop.

The invention will be explained with reference to the drawings.

The multi-channel communication device 10 of the present invention shown in FIG. 1 includes an amplitude modulation (AM) radio receiver 11 and a citizen band (CB)
A transmitter 12, a citizen's band (CB) receiver 13, and a tuning control circuit 1 for these citizen's band transceivers 12 and 13
4 and various control circuits that control the operation mode of the communication device 10.

Such a multichannel communication device is typically used by being installed in a vehicle such as an automobile. Operating power for the communication device 10 is supplied from a storage battery 15 coupled to an on/off switch 16 .

Switch 16 is shown as a two-position switch and, when in the on position, provides operating power, typically a positive voltage, to voltage regulation circuit 17, which in turn provides mode selection circuit 20.
so that a regulated constant voltage can be supplied to terminals 18 and 19 of. The storage battery 15, the on/off switch 16 and the voltage regulation circuit 17 only act to selectively supply a regulation voltage to the terminals 18 and 19 of the mode selection circuit 20 when the switch 16 is in the on state. The mode selection circuit 2 is basically a multi-channel communication device 10.
Choose from three modes of operation.

That is, in the first operating mode, only signals in the AM broadcast band are received, and the CB transmitter 12 and the CB receiver 13 remain inactive. In a second mode of operation selectable by mode selection circuit 201, multichannel communication device 1
Only the CB signal is transmitted and received from the river, and the AP receiver 11 remains inactive. A third mode of operation, selectable by mode selection circuit 20, allows AM signals to be received, but gives priority to transmitted and received CB signals over received AM signals. FIG. 1 shows a typical example of such a mode selection circuit 20.

In this example, a two-position CB-AM switch 19a is provided in the mode selection circuit 20, and its terminal 19a is connected to the wiper arm section 1.
Connect to 9a. In this case, the switch and its wiper arm (operator) are designated by the same reference numeral 19a. The AM position of switch 19a connects terminal 19 directly to terminal 21, which in turn connects directly to terminal 11a, thereby providing operating power to AM receiver 11. When the CB-AM switch 19a is set to the CB position, the terminal 19 is directly connected to the terminals 22 and 23. Terminal 22 is the squelch gate signal selection circuit 25
Connect directly to. This squelch gate signal selection circuit 25
The operation will be explained in detail later. Terminal 23 is directly connected to transmit/receive switch 26.

This switch 26 is constituted by a two-position selection switch having a wiper arm 26a. When the wiper arm 26a is switched to one position, the terminal 23 is connected to the terminal 27 via the terminal R.
This supplies operating power to the CB receiver 13. When the wiper arm 26a is switched to the other position, the terminal 23 is connected directly to the terminal 28 via the terminal T, thereby supplying operating power to the CB transmitter 12. The switch 26 therefore allows selection of the transmission mode or the reception mode for the CB transceivers 12 and 13 of the multichannel communication device 10. The mode selection circuit 20 is also provided with a two-position monitor switch 18a whose wiper arm is directly connected to the terminal 18.

In one operating position of this monitor switch 18a, terminal 1
8 directly to terminal 23. The other operative position of monitor switch 18a connects terminal 18 to the idle terminal. Therefore, the mode selection circuit 20 and the transmission/reception switch 26
Power can be selectively supplied to the AM receiver 11, the CB transmitter 12, and the CB receiver 13. That is, in the first mode of operation, power is supplied only to the AM receiver 11, and in the second mode of operation, power is supplied only to the CB transmitter 12 or the C8 receiver 13. In the third operating mode, power is supplied to the AM receiver 11 and the CB
It is also supplied to either the transmitter 12 or the CB receiver 13. Thus, mode selection circuit 20 and transmit/receive switch 26 effectively determine which of basic communication circuit sections 11-13 may be activated when on/off switch 16 is in the on position. The tuning control circuit 14 is CB
It couples to both receiver 13 and CB transmitter 12 .

The tuning controller 14 provides signals to the CB receiver and the CB transmitter to step-step tune the circuits to any one of a predetermined plurality of separate channel frequencies at separate frequency steps. be able to. The squelch gate signal selection circuit 25 is connected to the AM receiver 11
from this receiver to the AM audio input terminal 20
to receive audio signals detected by the user.

Further, this squelch gate signal selection circuit 25 selects the CB signal detected from the CB receiver 13 to the CB audio input terminal 31.
Enable to receive audio signals. Further, the squelch gate signal selection circuit 25 receives a sudden squelch control voltage from the CB receiver 13 at its terminal 32, and also receives a sudden squelch control voltage from the CB receiver 13 at its terminal 32.
3, a delayed squelch signal is received from the CB receiver 13. The audio signal is selected by the squelch gate signal selection circuit 25.
The selected audio signal is generated at the audio output terminal 34. This power terminal 34 is connected to a speaker 6 via an audio amplifier 5. Basically, the squelch gate signal selection circuit 25 is connected to the AM receiver 11 or C
Audio input signals may be received from any of the B receivers 13, and control signals extending to terminals 24, 32, and 33 determine which of these audio signals appears at audio output terminal 34. AM receiver 1 1 transmits an AM radio frequency (RF) signal to its AM antenna 1.
receives an input signal.

These signals are supplied to the RF amplification stage 2, the amplified signals are supplied to the tunable mixing/intermediate frequency (IF) stage 3, and the tunable mixing/intermediate frequency (IF) stage 3 is connected to the detection circuit 4, which receives the signal. The audio signal detected from the AM signal is supplied to the audio input terminal 301 of the squelch gate signal selection circuit. That is, the AM receiver 11 includes an RF amplifier 2, a tunable mixing/IF stage 3, and a detection circuit 4. It is contemplated that tuning of the AM receiver 11 may be accomplished by any standard AM tuning mechanism capable of continuously tuning the AM receiver over the entire AM broadcast band. This is why A
M receiver 1 1 is the type of AM commonly used in automobiles.
The radio receiver may be a radio receiver, and its circuit sections 2 to 4 may also be conventionally known. Mylophone 3 is attached to the CB transmitter 12.
5 is provided, and this is connected to the modulation circuit 3 via the audio amplifier 36.
Connect to 7. A modulation circuit 37 is connected to the tuning control circuit 14 so as to provide a carrier frequency signal for the CB transmitter. Also, the output end of the modulation circuit 37 is connected to the RF amplifier 38.
It is connected to the transmitting/receiving switch 40 via. These circuit sections 35-38 generally constitute a CB transmitter 12, which transmits a transmitted signal to switch 40 at a channel frequency determined by the carrier frequency signal received from tuning controller 14 when power is supplied to active power supply terminal 28. be able to supply. Circuit section 35 configuring the CB transmitter 12
The operation and configuration of 38 to 38 are the same as those conventionally known.
This actuator 40a is a two-position mechanical switch having a
is caused to mechanically move with the actuator 26a of the transmitting/receiving switch 26.

Wiper arm 40a is directly connected to CB antenna 41. Therefore, when the switch 26 supplies operating power to the CB receiver 13, the switch 40 connects the antenna 41 to the receiver 13. Also, the switch 26
When supplying operating power to the transmitter 12, the antenna 41 is connected to the transmitter 12 through the switch 4. The switches 26 and 40' thereby ensure that the antenna 41 can be connected to either the transmitter or the receiver to be activated. The C8 receiver 13 is provided with an RF amplifier 42 so that it can receive an RF input signal from an antenna 41 via a switch 40.

A first mixing stage 43 is connected to the RF amplifier 42 so that it can be supplied with an amplified RF signal. The first mixing stage 43 is also supplied with a first mixed frequency signal from the tuning control circuit 14 . This first mixing stage 43 synthesizes these two input signals and generates a first intermediate frequency (IF) signal (10.698).
This 11F signal is supplied to the second mixing stage 45 through the 11F filter 44.

This second mixing stage 45 is also connected to the tuning control circuit 14 so that it can receive these second mixed frequency signals. The second mixing stage 45 combines the second mixed frequency signal and the 11F signal to generate a 21F signal (45 Hz), and supplies the 21F signal to the 21F filter 46. 21st
A middle amplifier 47 is connected to the F filter 46, and this amplifier 4
After amplifying the 21st F signal arriving by 7, the detector 4
Supply to 8. The second m-th signal is demodulated by the detector 48 to generate a detected audio signal, and this signal is supplied to the CB audio input terminal 31. A direct current automatic gain control (DCAGC) signal is also generated at the terminal 49 by the amplifier 47.

The magnitude of this AGC signal is determined by the RF amplifier 42
1 is related to the strength of the RF input signal received from 1. AGC
Terminal 49 is connected in feedback to RF amplifier 42 so that the gain of this amplifier can be controlled by the amount of signal feedback. Circuit sections 42-48 constitute a standard dual (transformed) superheterodyne receiver, each of which is known in the art. It is also known to feed back the AGC voltage to control the gain of an RF amplifier. In a preferred example of the present invention, these first mixing stages 43,
A single integrated circuit (RCA circuit CA
308 hem type) is used. Further, the AGC terminal 49 is connected to the squelch trigger circuit 50.

This squelch trigger circuit receives the AGC signal and
A logic high or low logic squelch signal can be generated at the output terminal 51 in response to whether the magnitude of the AGC signal is above or below a predetermined squelch limit voltage. The output terminal 51 is the squelch gate signal selection circuit 25
directly connected to the control terminal 32 of. The signal at output terminal 51 responds quickly as the AGC signal changes magnitude relative to the predetermined squelch limit voltage. Therefore, this signal is called a quick squelch signal. Further, the output terminal 51 is connected to a squelch delay circuit 52.

This squelch delay circuit 52 receives the quick squelch signal and generates an output signal at a terminal 53. This output signal is supplied to the tuning control circuit 14 and also to the terminal 33 of the squelch gate signal selection circuit 25. The signal at terminal 53 responds quickly to a change in the polarity of the signal at terminal 51, but responds with a delay to a change in the polarity of the signal at terminal 51. Therefore, the signal at terminal 53 is called a delayed squelch signal. CB receiver 13 generally by circuit sections 42-45
is constructed and its operation will be explained below.

When the operating voltage is supplied to the part 27 of the CB receiver 13, the RF
Amplifier 42 receives the signal from antenna 41 . Amplifier 42 amplifies these signals and supplies them to first mixing stage 43 . The first matching stage 43 is also supplied with one signal out of a plurality of predetermined individual channel signals from the tuning control circuit 14. These received channel signals and input signals are mixed with each other by the first mixing stage 43, and an 11F signal having a frequency of about 10.69 arcs is obtained by conversion on the high frequency side.

This first signal is supplied to the second mixing stage 45 and mixed with about 10.24M signals from the tuning control circuit 14. In this way, a 21F signal having a frequency of 45 Hz is generated and this signal is supplied to the m amplifier 47. The IF amplifier 47 is the eleventh
An AGC signal is generated that is related to the magnitude of the received R signal that gives rise to the F' signal.

If the AGC signal at terminal 49 is greater than the predetermined squelch limit voltage, a high logic signal is generated at terminal 51 and hence at terminal 53, so that the squelch gate signal selection circuit 25 causes the CB audio signal at terminal 31 to be output to the audio output terminal 34. However, any AM audio signal at terminal 30 is not allowed to reach output terminal 34. If the AGC signal at terminal 49 is less than the predetermined squelch limit voltage, a low logic signal is generated at terminal 51. This low logic signal prevents the CB audio signal from passing from terminal 31 to terminal 34. The high logic signal at terminal 53 is delayed for a predetermined amount of time before it expires. This delayed high logic signal prevents the AM signal from passing from the AM input terminal 30 to the audio output terminal 34 for the predetermined period of time. After the end of this predetermined time, the CB receiver 1
3 does not receive the CB signal and a high voltage indicating that the AM signal is not required is not supplied to the terminal 24, the squelch gate signal selection circuit 25 causes the audio signal of the AM terminal 30 to pass to the audio output terminal 34. do it like this. The detailed operation of the squelch gate signal selection circuit 25 will be explained in detail later with reference to FIG. The tuning control circuit 14 is provided with a manual electronic channel selection switch 55, and this switch 55 is connected to a single actuator (wiper arm) 5.
5a is a mechanical three-position switch.

The manual switch 55 has a wiper arm contact terminal 56 connected directly to ground, an intermediate (pause) terminal 57 not connected to any circuit section, an upper scan terminal 58 and a lower scan terminal 59 each connected to a control circuit 60. establish. When no pressing force is applied manually to the actuator 55a, the actuator is always mechanically biased by 1, so that the terminal 56
and 57 are electrically connected to each other. When applying manual pressing force to the actuator in one direction, the actuator
Since the terminal 58 is moved to the position, the terminal 58 is directly grounded through the operating element 55a. When the manual pressing force is released, the actuator returns to the rest position and the terminal 57 is grounded. When a manual pressing force is applied to the actuator in the opposite direction, the actuator moves to the second position so that the terminal 59 is directly grounded. When this manual pressing force is released, the actuator returns to the rest position again. The other manual channel selection switch 55' is connected to the switch 55 in a redundant manner.

That is, switch 56' is of exactly the same construction as switch 55, is located remote from switch 55, and its components are electrically connected directly to the associated components of switch 55. Therefore, the actuator 55a or 55
Terminal 58 or 59 can be grounded by moving a'. The control circuit 60 generates an upward scan control signal when the actuator 55a is in the first position and generates a downward scan control signal when the actuator 55a is in the second position in response to the operation of the manual selection switch 55; In addition, the actuation enable control signal is generated even if the actuator 55a is in either the first or second position. This control circuit 60 terminates the enable control signal when the actuator 55a returns to its rest (third) position (connection terminal 57). A control circuit 6, described in detail below with respect to FIGS. 5, 6, and 7, is connected to the frequency synthesizer 61 and provides a plurality of control signals to the synthesizer 61 in response to the scan up, scan down, and enable control signals. By this synthesizer 61, the CB receiver 13
and the CB transmitter 12 with the first and second mixed frequency signals. The frequency of the signal supplied from the synthesizer 61 to the CB transmitter 12 and the CB receiver 13 is determined by a control signal supplied from the control circuit 60 to the frequency synthesizer 61.

At each separate step, the signals provided by the synthesizer 61 tune either the transmitter 12 or the receiver 13 to any one of the plurality of separate channels on which the transceiver is intended to operate. . That is, such tuning is performed by the control circuit 6 by the frequency synthesizer 61.
This is achieved by selectively generating any one of a plurality of predetermined separate channel signals, each having a different frequency, in response to a control signal from zero. For this purpose, control circuit 60 controls the frequency of the channel signals that synthesizer 61 supplies to transmitter 12 and receiver 13, so that the frequency of these channel signals determines the channel to which the transceiver is tuned. Control circuit 60 is responsive to the presence or absence of the enable control signal and the upscan control signal or the downscan control signal to control each of the plurality of separate schedules in either the first or second schedule sequence at each separate step. Frequency synthesizer 61 is successively stepped through each of the channel signals.

The selection of which of the two predetermined sequences to adopt depends on whether an upscan or downscan control signal is present.

Such a continuous sequential step process may be initiated by moving the operator 55a to its first (upward scan) or second (downward scan) position and the operator 55a.
Such steps continue until the enable control signal is terminated by returning a to its rest (third) position. Control circuit 60' is a digital channel visual display device 62
, thereby allowing the control circuit 60 and frequency synthesizer 61 to provide a visual numerical representation of the selected channel to the transmitter and receiver. Channel selection switch 55 is designed as a "manual" channel selection switch. This is because the termination of the sequential channel selection process is primarily controlled by the mechanical position of the operator manually moved by the operator of the communication device 10. Thus, a "manual" channel selection switch allows selection of any of a plurality of channels on which the transceiver is to be activated in response to manual control of its operator. In this respect, an "automatic" channel selection or channel scanning circuit is defined as a circuit that is responsive only to the mechanical position of an actuator that can be manually controlled and is not capable of selecting any one of a plurality of predetermined separate channel signals. shall mean. An automatic scanning circuit 63 is provided in the tuning control circuit 14 and connected to the control circuit 60.

The automatic scan circuit 63 continuously supplies the control circuit 60 with an enable control signal and either an upper scan or a lower scan control signal. However, automatic scanning circuit 6
3 is activated, the enable control signal provided to control circuit 6 is terminated by a high logic signal at terminal 53, which is connected directly to control circuit 60. Therefore, in the auto-scan mode, the tuning control circuit 14 receives a signal on the citizen band channel to which the auto-scan circuit is inactive or tunes the receiver 13 at each separate step, and the received signal is applied to the terminal 53. The transmitter 12 and receiver 13 are successively stepped through all of the predetermined operational channels of these circuits until a high logic signal is generated. When the received citizen's band signal ends, the squelch delay circuit 52 holds the voltage at the terminal 53 at the previous high level for a predetermined period of time, so automatic scanning does not immediately resume even after the received citizen's band signal ends. This allows the CB to be accepted for the transmitted signal by automatic scanning to the CB receiver.
Each of the channels can be explored. When a signal is detected on a channel, the communication device locks onto this channel and monitors this channel until the signal ends. If no further signal is received on this channel within a predetermined period of time after the last received signal ends, automatic scanning will begin again. Automatic scanning display 64
are connected to the automatic scanning circuit 63 in duplicate.

This auto-scanning indicator allows a signal regarding the operating status of the auto-scanning circuit 63 to be visually displayed to the operator of the communication device 10. In most cases, it will be necessary for the operator of the communication device 10 to visually display the operating characteristics of the automatic scanning circuit 63 to identify when the channel being listened to on the CB receiver is tuned by the manual selection circuit 55 or the automatic scanning circuit 63. be. If the transmitter/receiver station is tuned by the automatic scanning circuit 63, the CB transceiver will automatically retune after some pause period that occurs after the termination of the received signal. This automatic retuning is unnecessary for the operator of the communication device. In this example, the tuning control circuit 14 is used for operation of the CB receiver and CB transmitter only at each of the predetermined plurality of separate channel frequencies.

Such tuning does not fall within the category of tuning used for standard AM and FM receivers. A standard receiver can tune continuously to any frequency over the entire intended range. If the transmitter is part of a communicator, federal coordination ensures that transmissions occur only on separate frequency channels. Certain types of federated coordination can also prohibit signals from being received on certain frequency channels. This is because the CB receiver and CB
There is a need to be able to tune the transmitter only to a plurality of predetermined channels and to be able to tune the transmitter only to a predetermined plurality of separate channel frequencies. The tuning control circuit 14 tunes to any one of the predetermined channels at each separate step and thus tunes to a standard AM channel.
This is completely different from the continuous tuning function used in FM radio. This also distinguishes the tuning control circuit 14 from an automatic frequency sweep circuit that continuously tunes an AM or FM receiver over all frequencies of a predetermined frequency band. The operation of the mode selection circuit 20 is controlled by the multichannel communication device 1.
The various operating modes used for 0' and how these operating modes are affected by manual channel selection switch 55 and automatic scanning circuit 63 will now be described. As previously described, the mode selection circuit 2 includes two independent two-position manual switches, namely a CB-AM switch 19a with a wiper arm connected to terminal 19 and a monitor with a wiper arm connected to terminal 18. A switch 18a is provided.

When on/off switch 16 is in the on position, voltage regulating circuit 17 supplies a regulated positive DC voltage to both terminals 18 and 19. CB-AM switch 19a is A
In the M position, terminals 19 and 21 are directly interconnected. In this AM position, the regulated voltage is supplied to the power supply terminal 11a of the AM receiver 11, thereby making the receiver 11 ready for operation. CB-AM switch 19
If the wiper arm of a is set to the CB position, connect terminal 19.
are connected directly to terminals 22 and 23, and no voltage is supplied to power terminal 11a of AM receiver 11. Therefore, although the AM receiver 11 cannot operate in such a state, power is supplied to the CS transmitter 12 or the CB receiver 13 via the transmit/receive switch 26. Additionally, a relatively high DC voltage is supplied to terminal 24 of squelch gate signal selection circuit 25 to prevent any audio signal that may be generated at terminal 30 from reaching audio output terminal 34. Monitor switch 1 of mode selection circuit 20
8a connects terminal 18 to an open circuit terminal in the first position and to terminal 23 in the second position.

When the CB-AM switch 19a is set to the AM position and the monitor switch 18a is set to the position where the terminal 18 is connected to the terminal 23, power is supplied to the AM receiver and either the CB transmitter 12 or the CB receiver 13 is connected. also supplied.
Also, no high voltage is supplied to terminal 24, so that the audio signal present at terminal 30 or 31 can be selected by squelch gate signal selection circuit 25 in response to control signals supplied to terminals 32 and 33. Such an operating mode is referred to as a monitor mode of the multichannel communication device 10. In this monitor mode, the AM audio signal is considered a non-priority audio signal and the audio output terminal 3 is output only when the CB receiver 13 does not detect any received CB signal.
It will appear in 4. Also, although not shown in FIG. 1, additional connection arrangements are provided to prevent squelch gate signal selection circuit 25 from selecting any audio signal to be produced at output terminal 34 during operation of the CB transmitter. Further, when the CB receiver 13 receives a signal of a tuned channel frequency in the monitor mode, an AGC signal is generated at the terminal 49.

If this AGC signal is larger than the predetermined squelch limit voltage, a logic signal is generated at the terminal 51 and this logic signal is supplied to the control terminal 32 to cut off the terminal 30 from the audio output terminal 34 and to output the terminal 31 to this output terminal. so that it can be connected to the terminal 34. Even if the received CB signal ends, the logic signal is held at the terminal 33 by the squelch delay circuit 52, but the control signal at the terminal 32 quickly ends. This disconnects terminal 31 from terminal 34, but causes squelch delay circuit 52 to delay reconnecting AM audio terminal 30 to output terminal 34 for a predetermined period of time, typically about 4 seconds. With this delay period suitably determined, the communication device 10 allows successive transmissions on the CB channel with a pause period of at most 4 seconds between these R-successive transmissions without producing an AM audio signal between successive transmissions. Make it possible to monitor. In such cases, it is undesirable to quickly switch to receive a non-priority AM signal. When the automatic scanning circuit 63 operates, the control circuit 601 operates the frequency synthesizer 61 to generate CB for each of a plurality of scheduled channels in separate steps.
The receivers 13 are tuned in sequence.

Therefore, when the automatic scanning circuit 63 is activated in the monitor mode, the multi-channel Chikasan signal unit 10 monitors the non-priority AM channel and continuously searches all of the plurality of CB channels for the priority CB signal. When the CB receiver 13 receives a CB signal, it generates a high logic signal at the terminal 53, which tunes the receiver 13 to the tuning channel. Make it possible to prohibit being synchronized. When the automatic scanning circuit 63 is in an idle state, the manual selection switch 55 controls the tuning of the CB receiver and transmitter to generate a high logic signal at the terminal 53 so that the next tuning is not inhibited. Make it. Otherwise, the communication device 10 will respond in the same way. Although some known devices monitor a single priority channel, these devices all monitor multiple priority channels and interrupt in response to a non-priority channel if a priority signal is not being received. It does not have the ability to generate audio signals.

From this point of view, the present invention can provide a CB transmitter/receiver and an AM radio sewing device particularly suitable for use in automobiles. When such a combination device is used in a motor vehicle, the operator of the communication device can monitor any signal transmissions occurring on any CB channel while receiving normal broadcasts when no CB transmissions are occurring. FIG. 2 shows a perspective view of the external appearance of the multichannel communication device 10 of the present invention.

In the drawings, the same parts as those in FIG. 1 are designated by the same reference numerals, and in the following drawings, the same parts are designated by the same reference numerals. In the communication device 10 shown in FIG. 2, the AM receiver 11, the CB transmitter 12, and the CB
The receiver 13 is housed.

The on/off switch 16 is a rotary switch and is attached to an inner control rotation shaft protruding from the left side of the front control panel 71 of the outer shell 70. Digital channel visual display device 6
2 is a light emitting diode (LED) indicator in FIG. The CB-AM switch 19a is shown as a second layer push button. The monitor switch 18a is also shown as a second calendar pusher. Furthermore, a memo 72 is provided on the front control panel 71, the function of which will be explained in detail later. Further, the actuator of the switch 63a that activates the automatic scanning circuit 63 is also shown as a push button.Furthermore, when the automatic scanning display 64 is in an operating state, a light 64a is used, and when power is being supplied to the CB transmitter 12, a light 73 is used. Indicated by Further, a rotation control device 74 is attached to an inner rotation shaft protruding from the right side of the front control panel 71.
This rotation control device 74 is used as a variable manual tuner of the AM receiver 11. This AM receiver 11 is also provided with a plurality of push buttons 75 so that tuning can be performed by these push buttons 75 as well. The manual CB channel selection switch 55 is a three-position rotary switch and is mounted on the outer rotary shaft surrounding the inner rotary shaft of the AM tuning control device 74 on the right side of the front control panel 71. The microphone 35 is located at a location away from the outer thickness 70 in FIG. 2, and a transmit/receive switch 26 is provided on this microphone.

This transmitting/receiving switch 26 is a two-position push-talk switch. The switch 55' is a three-position rotary switch and is attached to the microphone 35. Therefore, the operator of the multi-channel communication device 10 can differentiate between each channel by adjusting the 3-position rotary switch 55 mounted on the outboard 7 or by adjusting the 3-position rotary switch 55' mounted on the microphone 35. The frequency of the CB channel can be manually selectively tuned. Therefore, when operating a communication device installed in an automobile, control shooting operations are often performed with only one hand. That is, when the operator of the communication device does not transmit a signal, the signal is sequentially transmitted to a number of different CB channels. According to the present invention, the operator of the communication device 10 can easily perform such operations. The reason for this is that by holding the microphone 35 with one hand and easily tuning to a desired CB channel with the thumb, and pressing the push button 26 with the thumb, the transmitter can be activated to transmit a signal to the tuned channel.
Therefore, when the communication device 10 is installed in a motor vehicle, an operator can easily tune the communication device to a vacant CB channel and transmit a signal on this channel without significantly affecting the operation of the motor vehicle. A typical example of the squelch gate signal selection circuit 25 is shown in FIG. In this example, the CB audio terminal 31 is directly connected to the control terminal 32 via a resistor 80, and a diode 6 whose cathode is connected to the terminal 81 is connected directly to the control terminal 32 via a resistor 80.
2 to the internal terminal 81.

Audio output terminal 34 is connected to terminal 8 via capacitor 83.
1 and the internal terminal 84 via the gondector 85.
Connect to. A voltage reference terminal 86 shown in the squelch gate signal selection circuit 25 is grounded via a cosonator, and a resistor 88
Connect the AM audio terminal 30 through the resistor 89.
It is connected to terminal 81 through. The terminal 84 is connected to the terminal 32 through a resistor 90 and to an internal terminal 91 through a diode 92 whose cathode is connected to the terminal 84 . terminal 9
1 is connected to terminal 86 via resistor 93 and to terminal 94 via capacitor 95. Terminal 94 is connected to terminal 30 via a diode 96 whose anode is connected to terminal 3. Further, the terminal 94 is connected to the terminal 33 through a resistor 97 and to the terminal 24 through a resistor 98 and a diode 99 connected in series. This diode 99 connects its anode to terminal 24. That is, these circuit elements 80
.about.99 constitute the squelch gate signal selection circuit 25. The operation of this squelch gate signal selection circuit 25 will be explained below.

A constant positive reference voltage is constantly applied to terminal 86. C
B. If only transmit/receive operations are required, a high (logic) voltage is applied to terminal 24 which reverse biases diode 96 and transfers the audio signal from terminal 30 to capacitor 9.
5 and 85 to the audio output terminal 34. When it is necessary to supply power to the AM receiver 11, no high voltage is applied to the terminal 24. Therefore, when no high voltage is applied to the control terminal 33, the diode 96 is forward biased. When operating only the CB receiver, a high voltage is applied to the control terminal 33 to ensure that the CB signal is received or is received within the last 4 seconds. A low (logic) voltage is applied to terminal 32 if no CB signal is received. This low voltage reverse biases diode 82 and forward biases diode 92. Due to this bias state,
The communication device 10 is in monitor mode and the last received CB
If the signal is terminated, connect the audio AM signal to terminal 30.
The output terminal 34 is made to pass through the output terminal 34. When the C8 receiver 13 detects a CB signal, terminals 32 and 3
3, a high squelch control voltage is generated.

The voltage at terminal 32 reverse biases diode 92 and forward biases diode 82, thereby allowing the CB audio signal to pass from terminal 31 to output terminal 34 and preventing the AM audio signal from passing to output terminal 34. As soon as the received CB signal ends, a low voltage is generated at the control terminal 32.
This low voltage reverse biases diode 82 and CB
Preventing audio signals from appearing at audio output terminal 34. However, for 4 seconds after the end of the CB signal, the terminal 33
High voltage remains. Therefore, the AM audio terminal 3 is not connected to the audio output terminal 34 for 4 seconds after the CB signal detected by the C8 receiver 13 ends.
Therefore, the receiver does not issue an interrogation voice for these four seconds, and therefore, the intermittent CB signal can be monitored by the communication device without confusing the sound generated by the AM audio signal being inserted between the received CB signals. In reality, the interval at which the receiver 13 sequentially receives the CB signals is 4 seconds or less. Typically CB
No more than 4 seconds elapse between two-way transmissions. The control terminal 32 and the diode 82 constitute a typical squelch gate for a received CB signal. However, such a cyclic pause period presents a complex switching function, which applies to all of the above-mentioned modes of operation of the multichannel communication device 10. FIG. 4 shows a frequency synthesizer 61 provided in the tuning control circuit 14.

Basically, the frequency synthesizer 61 consists of a programmable phase-locked loop with a crystal reference oscillator 100. This crystal oscillator is directly connected to the second mixing stage 45 to provide a second mixed signal to the CB receiver 13. Further, this crystal oscillator 100 supplies a reference frequency signal to a fixed frequency divider circuit 101, and the signal frequency-divided by this frequency divider circuit 101 is sent to a phase detector 102.
supply to. The phase detector 102 is also supplied with a signal from a programmable frequency divider 103.
The frequency division is performed using a plurality of connections 60 from the control circuit 60.
a and the connection to the transmission power supply terminal 28.
A phase detector 102 compares the signal from the fixed frequency divider 101 with the signal from the frequency divider 103 to generate another signal, which is passed through a low-pass filter 105 to a voltage controlled oscillator (VCO) 104. supply Voltage controlled oscillator 10
The outputs of 4 are supplied to the differential mixing stage 106, another frequency transmitting mixing stage 107 and the first mixing stage 43 of the CB receiver 13, respectively. A differential mixing stage 106 mixes the output signal of the voltage controlled oscillator 104 with the signal from the fixed frequency multiplier/divider circuit 108 . This circuit 108 receives the signal from the crystal oscillator 100 and produces an output signal whose frequency has a constant relationship to the frequency of the crystal oscillator. The output of the differential mixing stage 106 is supplied to the frequency divider 103.
The mixing stage 1 also transmits the output signal of the crystal oscillator 100.
Also supplied to 07. The phase-locked loop of the frequency synthesizer 61 includes a voltage-controlled oscillator 104 and a low-pass filter 1.
05, phase detector 102, programmable frequency divider 10
3 and a differential mixing stage 106.

A reference signal is supplied to the phase detector 102 from a crystal oscillator 100 via a fixed frequency divider 101. The reason for using this differential mixing stage 106 is that the output signal of the voltage controlled oscillator is frequency-downgraded by mixing, and the low frequency input signal is passed to the frequency divider 103.
It is in order to be able to supply the This allows the programmable frequency divider to easily process the input signal and the frequency synthesizer to precisely control the frequency of the signal supplied to the CB transceiver. The output signal of the crystal oscillator 100 has a frequency of 10.2 Obataz
Toshiko's signal is mixed with the first signal (10.699M ratio) to directly generate the second signal with a ratio of 45M. A fixed frequency divider 101 lowers the frequency of the signal from the crystal oscillator 100 and supplies it to a phase detector 102 for comparison. In a preferred embodiment of the present invention, the phase detector 102
The frequencies of the signals respectively supplied from the fixed frequency divider 101 and the frequency divider 103 are assumed to be Hz. A control signal from the control circuit 60 is supplied to the tube divider 103 via the conductor 60a, and this signal controls the frequency division of the frequency divider.

Next, the output signal of this frequency divider 103 causes the VCOI04 to
control the frequency of The reason is that the phase-locked loop until the arc Hz signal is generated by the frequency divider 103 is
This is because the frequency of the signal I04 is changed. A frequency multiplier/divider circuit 108 performs frequency multiplication and division of a certain combination, and a differential mixing stage 106 supplies a signal with an appropriate difference frequency to a frequency divider 103 . Since the general principles of phase-locked loops are known, a detailed description of the configuration of each of the different circuit elements shown in the block diagram of FIG. 4 will be omitted here. When the CB transmitter is activated, a positive logic signal is supplied from the power supply terminal of the transmitter 12 to the frequency divider 103. Therefore, the frequency division ratio of the frequency divider 103 can be changed from an even number to an odd number. Such a change in the frequency division ratio is necessary because a specific frequency is included. The frequency divider 103 of the transmitter 12 is also provided with various different signals during operation. The reason is that VCOI04 requires signals of different frequencies during transmission. The output signal from VCOI 04 is provided to a transmit mixing stage 107 where it is mixed with the signal from crystal oscillator 100 and the output signal is provided to modulator 37 of CB transmitter 12 . Frequency synthesizer 61 generates any one of a plurality of predetermined separate channel signals in response to a control signal from control circuit 60 and selection of a transmit or receive operating mode of the CB transceiver. The signal can be supplied to the CB transmitter 12 or the CB receiver 13.

The channel signals thus generated tune each of these circuits to one of the frequencies of the intended plurality of operating channel signals. Thus, the frequency synthesizer generates each separate channel output signal in response to each different combination of control signals generated from control circuit 60 and arriving via conductor 60a. When the control circuit 60 generates a series of different signals, the synthesizer 61 generates a plurality of separate channel output signals each having a predetermined frequency difference over the previous output signal. Make only the difference. This provides an arrangement in which the synthesizer 61 can sequentially step the tuning of the CB receiver 13 and the CB transmitter 12 over each of a plurality of separate channels in predetermined frequency steps. Next, the control circuit 60 is activated and the manual channel selection switch 5 is activated.
5 and the interaction of automatic scanning circuit 63 will now be described first generally and then in detail.

Control circuit 60, digital channel visual display device 62
An example of the automatic scanning circuit 63 will be explained with reference to FIG.

Basically, a control circuit 6 receives signals from a large number of various circuits, generates an output signal, and supplies this signal to a digital display device 62 and a synthesizer 61. That is, the output signal of the control circuit 60 is supplied to a plurality of conductive wires 60a connected to the synthesizer 61, and the output signal supplied to the digital display device 62 causes two separate light emitting diodes constituting the display device 62. The numerical display devices 110 and 111 consisting of the following are controlled separately. Control circuit 60
Terminals 58 and 59 of the manual channel selection switch 55, the output terminal 53 of the squelch delay circuit 52, the automatic scanning circuit 63, and the transmit terminal 28, which has a high (logic) voltage when the CB transmitter 12 is activated. Receives input signals from and respectively. These input signals control the output signals of the control circuit 60 to provide all the functions described above. The control input signals from the manual selection switch 55, the control terminal 53, and the automatic scanning circuit 63 are first supplied to the signal processing circuit 112 of the control circuit 60, which processes these signals and performs the first and second addition/subtraction (up/down). ) providing control signals to counters 113 and 114;

These counters supply logical counting (control) signals via a plurality of conductors to a read-only storage circuit 115 and two identical digit drivers 116 and 117, respectively, which digit drivers are connected to numeric displays 110 and 111. to drive these indicators. The control circuit 601 also includes an illegal channel detection circuit 119, which prevents the counters 113 and 114 from supplying erroneous control signals to the private storage circuit. Furthermore, the control circuit 601 is provided with a zero channel detection circuit 118,
This monitors all of the control signals supplied from counters 113 and 114 to prevent all of these control signals from becoming zero at the same time. Essentially the signal processing circuit 11
2 controls the operation of counters 113 and 114 which provide sequential control signals to read-only storage circuit 115 and digit drivers 116 and 117 during tuning. The memory circuit 115 receives the output signal of the counter, processes it, and generates a synthesizer control signal on the plurality of conductive wires 60a. Circuit section 112-1
19 constitutes the main part of the control circuit 60. The signal processing circuit 112 is provided with a diode 120 whose cathode is connected to the terminal 58 and whose anode is connected to the terminal 121 via a resistor 122.

Diode 123 also has its cathode connected to terminal 59 and its anode directly connected to the anode of diode 120 .
Terminal 121 or parallel connection capacitor 25 and resistor 1
26 to the positive voltage supply terminal 124. terminal 12
A resistor 127 is connected between 4 and 59, and terminal 59 is connected to preset terminals 129 and 130 of counters 113 and 114, respectively, through an inverting circuit 128. Further, terminal 59 is directly connected to addition/subtraction (up/down) control terminals 131 and 132 of counters 113 and 114, respectively. Terminal 121 is connected directly to one input terminal of NOR logic gate 133 whose output terminal is connected to clock pulse receivers 134 and 135 of counters 113 and 114.
Connect to each. Reference clock pulse generator 136
provides a clock pulse to one input terminal of NOR logic gate 137 and connects the output terminal of NOR gate 137 to the other input terminal of NOR gate 133. Further, the terminal 53 is directly connected to the other input terminal of the NOR gate 137, and this other input terminal is further connected to the automatic scanning circuit 63.
Also connect to. Therefore, these circuit elements 120 to 128,
Signal processing circuit 11 with 133, 136 and 137
2. In the absence of a high logic signal at terminal 53, NOR gate 137 connects to clock pulse generator 136.
It receives clock pulses from the NOR gate 133 and supplies these pulses to the NOR gate 133.

These clock pulses are provided to counters 113 and 114 through NOR gate 133 only when terminal 121 is in a low logic state (low voltage). This is terminal 1
The low logic signal at 21 is referred to as the "ready" control signal. This is because this low logic signal allows clock pulses to be provided to counters 113 and 114. When either terminal 58 or 59 is at ground potential, one of diodes 120 or 123 is forward biased;
As a result, the potential at terminal 121 changes to resistors 126 and 122.
and the magnitude of the positive voltage at the power supply terminal 124.

The resistor 122 is typically 1500, but the resistor 126
and 127 is typically 100KQ. Therefore, when ground potential is applied to terminal 58 or 59, a low potential, or ground potential, is generated at terminal 121 which causes clock pulses to be applied to counters 113 and 114 through NOR gate 133. When ground potential is substantially removed from both terminals 58 and 59, the voltage at terminal 121 gradually rises to the potential at power supply terminal 124. The reason is that capacitor 125 is resistor 12
This is because it is discharged by the current flowing through 6. Therefore, manual channel selection switch 55 (or switch 55') applies ground potential to either terminal 58 or 59 and generates an enable signal at terminal 121. When the ground potential is supplied to the terminal 58 by the switch 55, the terminals 131 and 132 of the counters 113 and 114
A positive (up) control signal is provided to .

The reason is that the resistor 127 is inserted and the diode 123
This is because separation is performed by When switch 55 provides ground potential to terminal 59, a low (down) control signal is provided to terminals 131 and 132. Therefore, depending on the mechanical position of the wiper arm 55a of the manual selection switch 55, an enable signal is generated when terminals 58 or 59 are supplied with ground potential, and switch 55 causes one of the terminals 58 or 59 to be brought to ground potential. is supplied, and counters 113 and 114
It also generates an upper or lower (scan) control signal that is supplied to the For example, if terminal 58 is supplied with ground potential, the clock pulse passes through NOR gate 133, thus providing a positive signal at terminals 131 and 132. The counters 113 and 114 are activated by this positive signal, and count sequentially in the addition direction in response to the clock pulse. As shown in FIG. 5, the automatic scanning circuit 63 is provided with a two-position mechanical switch 63a having an actuator wiper arm that is directly grounded. When the mechanical switch 63a is turned off, the terminal 53 is
The ground potential is now supplied to the portion 138 that is coupled to the ground. In such a position, autoscan circuit 63 prevents the voltage at terminal 53 from reaching a value high enough to prevent clock pulses from passing through NOR gate 137. When the switch 63a of the automatic scanning circuit 63 is in the scanning position, the ground potential is removed from the terminal 138 and supplied to the terminal 140. This terminal 140 connects directly to terminal 58. Thus, when switch 63a is in the scan position, a high logic signal generated at terminal 53 by squelch delay circuit 52 prevents clock pulses from passing through NOR gate 137. Further, by continuously supplying this ground potential to terminal 58, an enable signal is continuously generated at terminal 121, and an upward (scanning) control signal is continuously generated at terminals 131 and 132. In this way, the automatic scanning circuit 63 outputs the signals from the clock pulse generator 136 to the counters 113 and 11.
4 and continuously supply clock pulses to terminal 53.
These clock pulses are successively counted by counters 113 and 114 in an additive counting order until a high logic signal is generated, thereby indicating the provision of a signal to the channel of the CB receiver 13 to be tuned. The counter 113 is provided with a carry terminal 141 and a carry out terminal 142, and this terminal 142 is connected to the carry terminal 14 of the counter 114.
Connect to 3.

The terminal 141 is grounded via a resistor 144 and the resistor 14
5 to the terminal 28. This terminal 28 is connected to the transmitter 1
2 is at a high logic potential when it is activated. Counter 113
and 114 are provided with reset terminals 146 and 147 which are interconnected and receive input from illegal channel detection circuit 119. Also counter 1
13 and 114 are provided with counting preset terminals 148 and 149, respectively. Further, the counter 113 is provided with output counting terminals 150, 151, 152 and 153, all of which are connected to the read-only memory circuit 115 and each of which corresponds to a count value of 1, 2, 4 and 8, respectively. The high logic signals are sequentially counted. Counter 114 is provided with two output terminals 154 and 155 for counting count values of 1 and 2, respectively. Also, terminals 154 and 1
55 is also directly connected to read-only storage circuit 115. In a preferred embodiment of the present invention, counters 113 and 114 are comprised of addition/subtraction counters of the Motorola integrated circuit MCI451. Both counters have the same construction and the related terminals are also the same as shown in FIG. 5, but in this case, unnecessary terminals are omitted to simplify the drawing. Clock pulses arriving at terminals 134 and 135 are counted by counters 113 and 114 connected and arranged as described above, and a composite count value of output terminals 150-165 is set.

Each counter counts from 0 to 9, and the count value is 10.
When this happens, a zero count value is output as the output, and a low logic signal is generated at the carry-out terminal, that is, the carry-out terminal 142 of the counter 113. The low carry-out signal from counter 13 is applied to the carry-out terminal 143 of counter 114, causing this counter 114 to respond to the same pulse to
2 to generate a low carryout signal. This is because clock pulse input terminals 134 and 135 are interconnected. For this reason, counters 113 and 114 are connected in cascade, and counter 114 alone provides 10
Count the th pulse. These counters are output terminal 15
The maximum count value of 39 from 0 to 155 is the capacity that can be layered. The logic signals at the output terminals 150-155 of the counter are applied to the read-only storage circuit 115 to generate signals associated with the plurality of conductors 60a, thereby generating the frequency synthesizer 61.
C to any of the plurality of separate channels.
This indicates whether the B receiver 13 or the CB transmitter 12 should be tuned.

- The dedicated memory circuit shall be a known circuit that is easily available. These circuits are basically configured to receive a set of logic signals as input and generate a corresponding set of logic signals as output. Output terminals 150 to 153 as digits (
These output terminals are connected directly to a digit driver 116 which monitors these output terminals and provides associated drive signals to the numeric display 110 for visual display of the cumulative count indicated by terminals 150-153.

Digit driver 117 is connected directly to output terminals 154 and 155 to enable numeric display 111 to perform functions similar to those described above. In the preferred embodiment of the present invention, numerical drivers 116 and 117 use integrated circuits MCI4558 manufactured by Motorola. The display device 62 directly displays the correct count values of the counters 113 and 114,
This is made to correspond to the display of the selected CB channel. When the CB transmitter is powered, a high positive voltage appears at the power supply terminal 28.

This high voltage provides a positive signal to the carry-in terminal 141 of counter 113, thereby ensuring that counters 113 and 114 are prevented from counting any additional clock pulses during the operating state of CB transmitter 12. Therefore, according to the invention, it is possible to automatically and completely inhibit the channel frequency of a selected transmitter from changing during operation of the transmitter. This is true regardless of the operating state of the automatic scanning circuit 63 or the manual channel selection switch 55.
This means that the channel frequency of the transmitter 12 cannot be changed during signal transmission. This completely and reliably prevents the operator of the multi-channel communication device from suddenly changing the frequency of the transmitter while transmitting. Such characteristics do not exist in any manually tunable transmitter known in the art. The reason is that these known transmitters do not allow manual tuning of the transmitter to be disabled during signal transmission. Changes in transmitter frequency during transmission occur by chance and not by the operator of the multichannel communication device. In conventional communication devices, such frequency changes occur during manual tuning control at the same time as signal transmission. If the operator of the multichannel communication device is inexperienced in its operation or accidentally touches the manual tuning control device during transmission, the transmission channel may change undesirably. If the transmit frequency changes during transmission, the transient response of the transmitter can become significant and thus damage the power output stage of the transmitter. Also, switching the frequency during transmission will cause frequency bounces and therefore many undesired transient signals with legal frequencies will be transmitted, which will continue until steady state is restored after switching the transmitter frequency. will be done. According to the present invention, it is possible to prevent both of the above-mentioned conditions from occurring. Generally, the counter 11 is detected by the illegal channel detection circuit 119.
3 and 114 produce undesired counts at output terminals 150-155, which prevent the CS transmitter and CB receiver from tuning to one of the intended plurality of separate communication channels. To prevent.

Currently, there are two channels of citizen band communication channels. When the counters 113 and 114 are connected in a predetermined manner, the maximum counting capacity is 39, so it is necessary to prevent frequency channels other than the effective 23 channels from being selected due to the extra count value. Such prevention can be accomplished by illegal channel detection circuit 119 and cloud channel detection circuit 118, which will be discussed below. NOR gate 156 has one input terminal connected to terminal 153 , the other input terminal connected to terminal 152 , and an output terminal connected to one input terminal of NAND gate 157 . NOR gate 158 also has both input terminals connected to terminals 150 and 151, respectively, and an output terminal connected to the other input terminal of NAND gate 157 and also to the input terminal of inverter 165. The output terminal of this NAND gate 167 is connected to one input terminal of a NAND gate 160 via an inverter 159. NOR gate 161 has both its input terminals connected to terminals 154 and 155, respectively, and its output terminal connected to NA
Connected to the other input terminal of ND gate 160. NAN
The output terminal of D gate 160 is connected to one input terminal of NAND gate 162, and the output terminal of NAND gate 162 is connected to presettable terminal 1 of counters 113 and 114.
63 and 164, respectively. These circuit elements 158 to 162 constitute a stolen channel detection circuit 118. Illegal channel detection circuit 1 19 has NOR
A gate 166 is provided, and one input terminal thereof is connected to an inverter 165.
The other input terminal is connected to the terminal 154, and the output terminal is connected to one input terminal of the NOR gate 167. N
The other input terminal of OR gate 167 is connected to terminal 155 via inverter 165. Also, the output terminal of the NOR gate 167 is the reset terminal 1 of the counter 113 and 114.
46 and 147, respectively. Illegal channel detection circuit 119 is provided by these circuit elements 165 to 168.
Configure. The operations of the millet channel detection circuit 118 and the illegal channel detection circuit 119 are as follows.

Counters 113 and 114 have their output terminals 150 to 15
When the zero count value is added to 5, a low logic signal is generated at the output terminal of the NAND gate 160. This is why NAND
The output of gate 162 becomes high potential and therefore counter 113
and 114 to generate high logic signals at preset terminals 163 and 164. When these preset terminals 163 and 164 are at a high potential, the count values of these counters are transferred to terminals 129 and 148 of counter 113 and counter 1.
14 terminals! 30 and 149 to be reset to the predetermined control value. Counters 113 and 114
When the cumulative count values of terminals 150 to 155 become zero, if these counters are counting in the addition direction, counter 1
The addition counts of counters 13 and 114 are set to 1, but when these counters are counting in the subtraction direction, the addition counts of counters 113 and 114 are set to 23. The reason is that during the presettable mode of these counters, the logic signals at terminals 148 and 129 are
0 and 151 respectively and terminal 149.
and 130 logic signals at output terminals 154 and 155
This is because they are transferred to each. The operation of the presettable mode of the addition/subtraction counter is well known and will not be described in further detail. Next, terminals 129, 130, 148
The states in which the logic signals 149 and 149 are generated will be explained below. When the cumulative count value of terminals 150 to 155 becomes 23 or more, the illegal channel detection circuit 119 activates the NOR gate 1.
A high logic pulse is generated at the output of 67. In this case, the high logic pulse of NOR gate 167 causes counter 11 to
3 and 114 to zero, and thus the zero channel detection circuit 118 connects these counters to terminal 12.
9, 130, 148, and 149. Therefore, by combining the illegal channel detection circuit 119 and the zero channel detection circuit 118, the counters 113 and 114
.about.23 can be sequentially counted in either the addition direction or the subtraction direction. Since a count value of zero or a count value of 23 or more is prohibited, the counter is automatically reset to an acceptable count value when any of these count values occurs. The reason for resetting the maximum count value of the counter to 23 is that only 23 citizen band channels are currently in use. Of course, if the number of channels is added in the future, the number of output terminals of the counter 114 can be added and the illegal channel detection circuit can also be designed to include these additional channels. However, the device of the present invention can be easily expanded to accommodate a large number of additional channels, each with a different frequency of interest.
Of course, other read-only storage circuits corresponding to the read-only storage circuits are also required for the additional channels. Closing on/off switch 16 to power the multi-channel communications device provides a high positive voltage to terminals 18 and 19 of mode selection circuit 20.

In FIG. 5, it is assumed that a terminal 18' corresponding to the terminal 18 is directly connected to the preset terminal 148. Therefore, when the count value of the counter 113 is preset, the terminal 18
The logic signal of ' is transferred to terminal 150'. Also, terminal 1
8' is also connected via a resistor 170 to a terminal 171 connected to the input terminal of the NAND gate 162. The terminal 171 is grounded through a capacitor 172 and connected to a terminal 174 through a resistor 173. Terminal 174 is capacitor 17
5 to ground, and the counter 11 via the inverter 176.
Connect to the preset terminal 149 of No. 4. Terminals 18 and 18' are identical. By closing switch 16, terminal 18' is initially supplied with a positive voltage.

This causes terminals 171 and 174 to initially be in a low logic state (voltage) and terminal 149 to be initially in a high logic state. These logic states are connected to capacitors 172 and 175.
is charged gradually, so it does not change suddenly. terminal 17
The low logic state of 1 presets counters 113 and 114 by NAND gate 162 in response to the initial closure of switch 16. This means that power switch 1
6 is closed, the counters 113 and 114 are closed, regardless of the count value counted during the previous operation of this power switch 16.
This means that can be set to a scheduled count value. In the preferred embodiment of the invention, the first actuation of switch 16 causes counters 113 and 114 to produce a count of 11.

The reason is that during the first preset of the counter terminal 149 is initially in a high logic state. The next successive presetting of counters 113 and 114 causes the composite count value of these counters to increase over the upward scan (
1 or 2 depending on the addition) or downscan (subtraction) signal
Set to 3. The reason why the preset count value changes as a result of successive preset processing is that the terminal 149 becomes a low logic state after the first preset that occurs due to the closing of the switch 16. Therefore, according to the present invention, C
The B receiver and transmitter tuning can be initially preset to channel 11, which is the universal paging channel for citizen band communications. i.e. channel 1
1 as the universal calling channel, all citizen band communications would occur on channel 11 and then switch to another channel when the call ends. Thus, according to the present invention, when power is first applied to a CB transceiver, the receiver and transmitter can be automatically tuned to this intended paging channel. If you do not need power in preset mode, use terminal 1 shown in Figure 5.
8' is connected directly to the storage battery, thereby providing a constant low voltage at terminal 149 and preventing the generation of power in the preset mode.

When so arranged, the tuning control circuit 14 acts as a mechanical switch so that the channel selected by the tuning control circuit remains in tune while powering the CB receiver and transmitter in the previous operation. Make sure the control circuit is the same as the previously selected channel. FIG. 8 shows a modification of a portion of the multichannel communication device of the present invention.

In this example, the operator of the communication device can select either a preset mode in the power supply mode or a channel storage mode of the tuning control circuit 14. It is important to make such choices. The reason for this is that in many cases the operator initially tunes the receiver and transmitter to the intended paging channel, but in other cases the operator tunes the CB transceiver intermittently to a particular channel (not the paging channel). This is because it is necessary to constantly monitor the
According to the configuration shown in FIG. 8, this function can be achieved. This point will be explained in detail later. FIG. 6 shows a modification of the signal processing circuit 112 and the automatic scanning circuit 63 together with an automatic scanning display device 64. In FIG.

In the modification shown in FIG. 6, circuit elements 121-128 are connected and arranged in the same manner as the associated circuit elements described with reference to FIG.

However, in this example, the terminal 58 is not connected to the automatic scanning circuit 63 but directly connected to the anode of the diode 123. The terminal 121 is also connected to the input terminal of a NOR gate 181 via an inverter 180. The output terminal of NOR gate 181 is connected to one input terminal of NOR gate 182.
The output terminal of NOR gate 182 is connected to counters 113 and 1
14, and the other input terminal of this NOR gate 182 is connected to a clock pulse generator 136. Also NOR gate 183
has its output terminal connected to the other input terminal of NOR gate 181, one force terminal connected directly to terminal 53, and the other input terminal connected to the Q terminal of flip-flop 190 of automatic scanning circuit 63. These circuit elements 121 to 128, 1
36 and 180 to 183 constitute a modification of the signal processing circuit 112 shown in FIG. In FIG. 6, the automatic scanning switch operator 63a of the automatic scanning circuit 63 is shown as a push button momentary contact switch.

It is assumed that this contact switch is always spring-biased at the rest position and supplies the ground potential to the terminal 191 only when the actuator 63a is pressed. Therefore, when the manual pressure is released, the actuator 63a returns to the rest position and the ground potential is no longer supplied to the terminal 191. In this example, a resistor 192 is connected between a terminal 191 and an internal structure 193, and this terminal 193 is directly connected to the clock pulse input terminal of the flip-flop 191. When this terminal 193 is grounded via a capacitor 194, a capacitor 95 and a resistor 1 are connected in parallel.
It is connected to the positive voltage terminal 124 via 96. The reset terminal R of flip-flop 190 is connected to the output terminal of NOR gate 197. This NOR gate 197 has one input terminal connected to terminal 28 through capacitor 98 and the other input terminal connected to terminal 23 through capacitor 199. Terminal Q of flip-flop 190 is resistor 200
It is connected to the base of the NPN transistor 201 through.
This NPN transistor 201 has its collector directly connected to the power supply positive terminal 18 and its emitter connected to a resistor 202 connected in series.
and ground through the light emitting diode 64a. These circuit elements 200-202 and 64a constitute an automatic scanning mode visual indicator 64, and circuit elements 190-199
The automatic scanning circuit 63 and switch 63a are configured by the following. - In this example, the size of the resistor 196 is typically set to 10
0KQ, and the magnitude of resistor 192 is 50KQ.

Therefore, the automatic scanning switch 63a including the actuator and the circuit elements 192, 195 and 196 constitute a switch anti-rebound device, which is connected to the manual channel selection switch 55 and the circuit elements 122, 125 and 12.
The device is almost the same as that formed by No. 6. Therefore, by manually operating the switch again, the operable signal can be easily generated at the terminal 193. The voltage at terminal 193 becomes progressively responsive to the switch being deactivated by flipping the switch or releasing the manual actuator. It is extremely important to prevent the switch for connecting this terminal 193 to the input terminal of the flip-flop 190 from flipping. The reason for this is that the extra switching pulses resulting from such a rebound would retrigger flip-flop 190 and thus not produce the desired result. In a preferred embodiment of the present invention, a capacitor 195 and a resistor 196 connected in parallel with the capacitor 195
Thus, the prevention of switch bounce can be satisfactorily achieved.

However, by using both capacitors 195 and 194, such bounce prevention can be better achieved. In practice, the use of both of these capacitors is sufficient to prevent the generation of transient signals due to switch bounces that trigger flip-flop 190. The operation of the portion shown in FIG. 6 is as follows. Terminal 58 or 59 by manual selection switch 55
Applying a ground potential to either of the terminals generates an enable signal at terminal 121 which is in a low logic state. Therefore, in response to manual operation of the channel selection switch 55, the NOR gate 181 always generates a low logic output. Therefore, regardless of the signal at the terminal 53 and regardless of the operating state of the automatic scanning circuit 63, the counter 1 passes through the NOR gate 182.
13 and 114 can be continuously supplied with clock pulses from a clock pulse generator 136. In the example shown in FIG. 5, assuming that the automatic scanning circuit 63 is in the scanning mode and a signal arrives at the channel to be scanned, before the manual channel selection switch 55 starts controlling the counts of the counters 113 and 114 again. It is necessary to shut off automatic scanning mode. This is not the case in the example shown in FIG. 6, as explained below. flip flop 19
It is assumed that 0 has two stable states as in the case of the characteristics of a general flip-flop.

That is, in one stable state, a high (logical) voltage is generated at the terminal Q, and this voltage is supplied to the transistor 201 to generate the scanning display light 64a. Similarly, in one stable state, a low logic signal is generated at terminal Q, and this signal is passed to N.
This signal is supplied to one input terminal of OR gate 183, and the signal from squelch delay terminal 53 is also supplied to the other input terminal of this gate 183. If manual channel selection switch 55 does not cause an enable signal to be generated at terminal 121 but a low logic signal is to be generated at terminal Q of flip-flop 190, NOR gate 182 selects terminal 5.
Clock pulses can be continuously provided to counters 113 and 114 until the voltage at 3 becomes high, indicating that receiver 13 is receiving the signal of the selected channel. No clock pulses are provided to these counters unless the logic state of flip-flop 190 changes during the reception of such a signal and unless an enable signal is generated at terminal 121 by manual channel select switch 55. When the actuator 55a of the manual selection switch is momentarily brought into contact with the terminal 58, an enable signal is generated at the terminal 121, thereby enabling clock pulses to be provided to the counters 113 and 114.

This allows the counts of these counters to be incremented and the receiver tuned to the next channel without disabling the autoscan mode controlled by autoscan circuit 63. This situation differs to some extent from the example shown in FIG. Therefore, by applying and releasing a pressing force acting in a single direction to the operating element 55a, the automatic scanning mode can be disabled without being put into an idle state. When the CB transmitter 12 is activated, a high voltage is generated at the terminal 28, producing a turn-on pulse that is applied to the NOR gate 197, thereby causing a flip-flop.

190 to a stable state. This stable state corresponds to a low logic signal at terminal Q and a high logic signal at terminal Q. Therefore, when the CB transmitter is activated, the automatic scanning device is inactive. Once the operator of multichannel communication device 10 has activated his transmitter, he will no longer attempt to scan all of the CB channels in search of someone else's transmissions. In this case, since the user first tries to confirm the response to his own transmission, he does not try to change the channel frequency of his own CB transceiver after transmitting. Flip-flop 190 is also set when power is first applied to terminal 23. Therefore, when the flip-flop 1901 is activated and the CB transmitter is activated, the operator of the multichannel communication device activates the operator 18a or 19a of the mode selection circuit 20 to select either the C8 receiver or the CMOS transmitter. Reset when power is first applied to the In the example shown in FIG. 6, capacitors 198 and 199 are connected to flip-flop 190.
Of course, other circuits similar to this can be used to generate the reset pulse. FIG. 7 shows a modification of the automatic scanning circuit shown in FIG. 6 together with a portion of the apparatus of FIG.

The automatic scanning display circuit 64 and signal processing circuit 112 shown in FIG. 7 have exactly the same configuration as the automatic scanning circuit 64 shown in FIG. 6 and the signal processing circuit 112 shown in FIG.
That is, the example shown in FIG. 7 is based on the automatic scanning circuit 6 shown in FIG.
This is a slightly modified version of 3. By making such a modification, the automatic scanning circuit 63 shown in FIG. 7 can be operated without being overridden by the actuator 55a of the active channel selection switch. In this respect, the operation of the circuit of FIG. 7 is the same as that of the circuit shown in FIG. In FIG. 7, circuit elements 190-196 of automatic scanning circuit 63 are connected and arranged in the same manner as described with respect to FIG.

In this example, a switch anti-rebound circuit made up of circuit elements 191-196 is used to supply clock pulses to the clock pulse input terminal of flip-flop 190 by operating element 63a. Terminal Q of flip-flop 190 is connected to the cathode of diode 120 through diode 205, and the cathode of diode 205 is directly connected to terminal Q of flip-flop 190. Terminal 53 is NOR gate 137
The input terminal Q of the flip-flop 190 is connected to the input terminal of the flip-flop 190 through a resistor 206 and a diode 207 connected in series.

Making such a connection prevents the voltage at terminal 53 from inhibiting clock pulses when autoscan circuit 63 is not in autoscan mode. The reason for this prevention is that when the automatic scanning circuit 63 is not in the scanning mode, the flip-flop 19
This is because the voltage at the 0 terminal Q is low and a high logic signal is prevented from being generated at the terminal 53. In this example as well, a drive signal is supplied from the terminal Q of the flip-flop 190 to the base of the transistor 201, thereby enabling the automatic scanning display circuit 64 to perform a visible display.

Further, the terminal Q of the flip-flop 190 is connected to one input terminal of a NAND gate 208, and the other gate of this gate 208 is directly connected to the transmitter power supply terminal 28. NA
The output terminal of the ND gate 208 is grounded through a resistor 209 and connected to a terminal 193 through a diode 210.
The anode of this diode 210 is directly connected to terminal 193. By connecting and arranging the CB transmitter 12 in this way
When the automatic scanning circuit 63 receives power, the automatic scanning mode of the automatic scanning circuit 63 is terminated. Termination of this automatic scanning mode is accomplished by generating a toggle pulse at the clock pulse input terminal of flip-flop 190 during transmitter operation without resetting flip-flop 190 using reset terminal R, also shown in FIG. Terminal 23 is connected to reset terminal R via capacitor 211 and inverter 212 so as to cause a reset pulse of flip-flop 190 when a positive voltage is first applied to terminal 23.

This ensures that the automatic scanning circuit 63 does not fall into scan mode when the CB transceiver is initially powered through the mode selection circuit 20. FIG. 8 shows a modification of a portion of the multichannel communication device 10 shown in FIG.

In this example, the storage battery 15 is connected to the on/off switch 16 and a positive voltage is supplied to it, whereby the voltage adjustment circuit 17,
Accordingly, while selectively supplying a positive voltage to terminals 18 and 19 of mode selection circuit 20, this storage battery is also connected to storage switch 215 so that it can be supplied with a positive supply voltage. This memory switch 215 is constituted by a mechanical two-position switch having an operating element 215a, so that the voltage of the storage battery can be selectively supplied to a terminal 216 according to the operating position of the operating element 215a. Terminal 216 connects to a voltage regulation circuit 217 having a resistor 218 connected between this terminal and internal terminal 219 . Also terminal 219
A Zener diode 220 is provided between the terminal 219 and ground, thereby generating a constant Zener voltage at the terminal 219. These circuit elements 218 to 22 constitute a voltage adjustment circuit 217. Terminals 18 and 19 are connected to terminal 18' through an isolation diode 221, and terminal 219 is also connected to terminal 18' through another isolation diode 222. That is, these diodes 221 and 22
2 connects its cathode directly to terminal 18' and
A capacitor 223 is connected between ' and the ground. Terminal 1
8' acts as a power supply terminal in the same manner as described with respect to FIG. 5, thereby controlling the turn-on preset mode of counters 113 and 114. As mentioned above, when connecting the terminal 18' directly to the storage battery 15, the counter 1
13 and 114 have a memory function and thus hold the previous count value until an additional clock pulse arrives.

When the terminal 18' is directly connected to the terminal 18, as is clear from the above description, when power is first supplied to the communication device by the on/off switch 16, the counters 113 and 114 are preset and the CB transmission is started. machine and receiver 13
The paging channel 11 can now be selected. According to the example shown in FIG. 8, both of these functions can be obtained by a single device. i.e. counter 1
13 and 114 to read the previous count value;
The ability to preset counters 113 and 114 to a particular call channel upon actuation of on/off switch 16 can be selectively selected by a single device.
The operation of the apparatus of FIG. 8 is as follows.

When the storage battery voltage is not applied to the terminal 216 by the memory switch 215 corresponding to the switch 72 in FIG. This is because actuation of switch 16 provides a power on-step pulse through diode 221 to terminal 18'. Counters 113 and 114 are thus preset. In this case, the isolation diode 222 prevents the output of the voltage adjustment circuit 17 from adversely affecting the voltage adjustment circuit 217. When the storage battery 15 is directly connected to the terminal 216 by the storage switch 215, a positive voltage is continuously supplied from the voltage regulating circuit 217 to the terminal 18' via the diode 222. In this case, the isolation diode 22
1 prevents this positive voltage from adversely affecting the operation of voltage regulation circuit 17 and also prevents power from being applied to terminals 18 and 19 of mode selection circuit 20. Then, when the on/off switch 16 is turned on, a voltage slightly higher than the above voltage is supplied from the voltage regulating circuit 17 to the terminal 18' via the diode 221. Thus, even if a slightly larger voltage is applied to terminal 18', the tuning control circuit 14 will not be preset to the preset paging channel. This is because a high logic signal is already provided to terminal 18' via storage switch 215 and voltage regulation circuit 217. Therefore, the circuit of FIG. 8 allows the operator of multichannel communication device 10 to
Either the preset function or the memory function of the CB tuner can be selected through the use of the CB tuner. 9th A and 9th
Figure B shows the operator 55a of the manual channel selection switch 55.
FIG. 6 is a waveform diagram illustrating the operation of a switch anti-rebound circuit using both the operating element 63a of the automatic scanning circuit 63 and the operating element 63a of the automatic scanning circuit 63.

In FIGS. 9A and 9B, the vertical axis represents voltage magnitude and the horizontal axis represents time. These waveforms show typical voltages developed at terminals 121 and 193 in response to switch actuation. However, in FIGS. 9A and 9B, only terminal 121 and switch 55 will be discussed. The reason is that the operation of the switch 63a and the waveform of the terminal 193 are different from that of the terminal 12.
This is because the waveform and operation of the switch 55 are exactly the same as those of No. 1. The actuator 55a operates and the terminal 58 or 59
The voltage at terminal 121 before contacting any one of terminal 124 is
is a high positive voltage equal to the voltage of

Time t. Terminal 58 or 5 is activated by operation of actuator 55a.
9 is grounded. This is because capacitor 125
Has low resistance! 22 and either diode 120 or 123 to create a minimum voltage y.・(Almost a drop value) occurs rapidly. When the actuator 55a returns to its rest position at time t after a sufficient period of time has elapsed, the voltage at the terminal 121 begins to gradually increase due to the discharge of the capacitor 25 via the resistor 126. 9th A
The figure shows terminal 12 when no switch bounce occurs.
1 voltage waveform is shown.

Figure 9B is a seasonal song. After closing the switch at time t2
The voltage waveform at the terminal 121 generated by the anti-rebound circuit is shown when the switch rebound occurs at time t3 and this rebound ends at time t3. These times t2 and t3 occur approximately immediately after time to. In this case, the voltage at the terminal 121 begins to gradually increase over time. However, since the switch contacts again in the next song 3, the voltage at the terminal 121 rapidly drops to the minimum value V, and remains at this minimum value until the operating element 55a returns to the rest position. Therefore, as is clear from the waveform in FIG. 98, the voltage generated at the terminal 121 is less affected by the bounce of the switch. The reason is that the voltage at the terminal 121 changes quickly in response to the actuation of the actuator and can be gradually recovered. This is an advantage of the anti-rebound circuit used in conjunction with the manual actuator 55a of the channel selection switch 55. Such a circuit is also used in automatic scan switch 63a shown in FIGS. 6 and 7. FIG. 10 shows a typical example of the squelch trigger circuit 50 and squelch delay circuit 52 of the multichannel communication device 10 shown in FIG.

This squelch trigger circuit 5W is a potentiometer 22
5 is provided, its fixed resistance element is connected between the terminal 49 and the ground, and the output tap is directly connected to the base of the NPN transistor 226.

The collector of transistor 226 is connected to receiver power supply terminal 27 via resistor 227 and directly to terminal 51 . In addition, the collector of the transistor 226 is connected to the NPN transistor 22 through a voltage dividing network 229 consisting of two resistors.
Connect to the base of 8. Transistor 228 has its collector connected directly to terminal 27 and its emitter connected to the emitter of transistor 226, with both emitters connected to ground through resistor 230. These circuit elements 225 to 23
0' thus constitutes the squelch trigger circuit 50. The squelch trigger circuit 50 receives the AGO signal at the terminal 49, compares this signal with an adjustable limit level, and outputs the AGO signal at the terminal 49.
A high output voltage is generated at terminals 51 and 32 when the C signal indicates that a CB signal has been received. The high voltage at this terminal 32 biases the diode 82 (FIG. 3) of the squelch gate signal selection circuit 25 in the forward direction, thereby transmitting the detected audio signal of the received CB signal to the speaker 6.
to allow it to pass through. Potentiometer 225 corresponds to the adjustable squelch control found in most two-way communication devices.

The control device is generally configured in a rotatable configuration to allow easy adjustment by the operator of the communication device. Accordingly, such an adjustable squelch potentiometer is shown in rotation view 225 in FIG. Basically, the squelch trigger circuit is in the form of a variable voltage comparator circuit that generates a high output voltage when the received voltage differs from an internal reference voltage by at least a predetermined difference.

The squelch delay circuit 52 is provided with a series support resistor 231 and a diode 232 between the terminal 51 and an internal terminal 233, and the internal terminal 233 is grounded via a capacitor 234.

Diode 232 has its cathode connected directly to terminal 233. In addition, the terminal 233 is connected to N via a resistor 235.
Connected to the base of PN transistor 236. Transistor 236 connects its emitter to NPN transistor 237
The collector is connected to the power supply terminal 27 via the resistor 238. Transistor 237 has its emitter connected to ground through resistor 239 and its collector connected to terminal 27 through resistor 240. Further, a PNP transistor 241 is provided, its base is connected to the collector of the transistor 237, its emitter is directly grounded, the collector is directly connected to the terminal 53, and the base is connected to the terminal 27 through the resistor 242.
Connect to. In response to the development of a high voltage at terminal 51 indicating that receiver 13 has received a CB signal, capacitor 234 is rapidly charged through the path formed by resistor 231 and diode 232.

The value of the resistor 231 is approximately IKQ. Diode 232 prevents capacitor 234 from discharging through resistor 231 when a low voltage is developed at terminal 51 indicating that the C mochi message is no longer being received. This causes capacitor 234 to discharge through the high impedance circuit of resistor 235 (3MO) and the input impedance of transistor 236. Capacitor 234 is initially charged by the high voltage at terminal 51 which causes transistors 236 and 237 to become conductive and transistor 241 to become non-conductive. When the signal at terminal 51 terminates, transistors 236 and 237 remain conductive due to the slow discharge of capacitor 234. This causes the high voltage at terminal 53 to also be maintained for some time after the termination of the signal at terminal 51. This delay time is typically 4 seconds as described above. As can be seen from the foregoing, the present invention provides a multi-channel communication system that significantly improves upon prior art systems and has many advantages.

It goes without saying that the present invention is not limited to the above-described example and can be modified in many ways.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an example of a multi-channel communication device of the present invention that can be manually tuned; FIG. 2 is a perspective view showing the outer shell and manual control device of the multi-channel communication device of FIG. 1; FIG. is a circuit diagram showing the configuration of the squelch gate signal selection circuit of the multi-channel communication device of the present invention, FIG. 4 is a block diagram showing the structure of the frequency synthesizer of the multi-channel communication device of the present invention, and FIG. 5 is a control diagram of the communication device of the present invention. FIG. 6 is a block diagram showing the configuration of the circuit, channel display device, and automatic scanning circuit. FIG. 6 is a circuit diagram showing the configuration of the automatic scanning circuit, automatic scanning display, and signal processing circuit of the communication device of the present invention, and FIG. Road map showing the configuration of the modified example, No. 8
9A and 9B are block diagrams illustrating the configuration of a tuned channel storage and/or tuned channel preselection circuit that may be incorporated into a communication device of the present invention, and FIGS. FIG. 10 is a waveform characteristic diagram showing a control signal generated by the prevention circuit. FIG. 10 is a connection layout diagram showing the configuration of the squelch trigger circuit and squelch delay circuit of the multichannel communication device of the present invention. DESCRIPTION OF SYMBOLS 10... Multichannel communication device, 11... AM radio receiver, 1 1a... Terminal, 1... AM antenna,
2... RF amplification stage, 3... Tunable mixing/intermediate frequency stage, 4... Detection circuit, 5... Audio amplifier, 6...
Speaker, 12... Citizen band (CB) transmitter, 13
... Citizen band (CB) receiver, 14... Tuning control circuit, 15... Storage battery, 16... On/off switch,
17... Voltage adjustment circuit, 18... Terminal (20), 18'
...terminal (20), 18a...2 position monitor switch,
19...Terminal (20), 19a...2 position CB-AM switch (actuator wiper arm), 20...Mode selection circuit, 21, 22, 23...Terminal (20), 25...
Squelch gate signal selection circuit, 26... Transmission/reception switch, 26a... Wiper arm (operator), 28...
- Operating power supply terminal, 30... AM audio input terminal, 31... CB audio input terminal, 32, 33.
...Input terminal, 34...Audio output terminal, 35...Microphone, 36...Audio amplifier, 37...Modulation circuit, 38...RF amplifier, 40...Transmission/reception switch, 40a...Wiper arm, 41... CB antenna,
42...RF amplifier, 43...first mixing stage, 44...
11th F mixing stage, 45... second mixing stage, 46... 21st F filter, 47... IF amplifier, 48. ．． ．． Detector, 49...AGC terminal, 50...Squelch trigger circuit, 51...Output terminal, 52...Squelch continuous circuit, 53...Terminal, 55, 55'...Manual electronic channel selection switch, 55a , 55a'... operating element (wiper arm), 56, 56'... wiper arm contact terminal,
57, 57'... intermediate (rest) terminal, 58, 58'...
...Upper scanning terminal, 59, 59'...Downward scanning terminal,
60...Control circuit, 61...Frequency synthesizer, 62...
・Digital channel visual display device, 63... Automatic scanning circuit, 63a... Push button (automatic scanning switch), 6
4...Automatic scanning display, 64a...Light emitting diode, 70...Outside transport, 71...Front control panel, 72...
...Memory push nail, 73...Light (light emitting diode), 7
4... Rotation control device, 75... Push nail, 82, 92,
96...Diode, 100...Crystal reference oscillator, 1
01... Fixed frequency divider circuit, 102... Phase detector, 1
03... Programmable frequency divider, 104... Voltage controlled oscillator (VCO), 105... Low pass filter, 106... Differential mixer, 107... Frequency transmission mixing stage, 108 ...Fixed Frequency Frequency Divider Circuit, 110
, 111... Numerical display, 112... Signal processing circuit, 1 13, 114... Addition/subtraction counter, 115...
Kendori dedicated memory circuit, 116, 117... digit driver, 1
18... Zero channel detection circuit, 119... Illegal channel detection circuit, 131... Terminal (113), 132...
...Terminal (114), 133, 137, 182, 183
...NOR logic gate, 13...Reference clock pulse generator★162...NAND logic gate, 170, 173.
...Resistance, 171,174...Terminal, 172,175
...Capacitor, 176,180...Inverter, 190...
Flip-flop, 215...Memory switch, 217...
・Voltage adjustment circuit, 221, 222...diode. 〃CoCh. 2? Hiro J Hiro, J Hiro, Shio rko []. 4 Kami Koko, 7 r Hiroki Yur Tachi 9 Yu #ko [9 Yur to 9, Sha

Claims (1)

[Claims] 1. Can be synchronized during manual operation by the first manual operation element 55a,
at least one receiving device 42-47, 55, 60, receiving a signal on a selected channel of each of the plurality of channels and generating an audible signal related to the received signal on the selected channel; 61; in response to the presence of a scanning enable signal coupled to the receiving device and including sequentially automatically tuning the receiving device in separate steps to each of the separate channels in a predetermined order; a device 50, 52, 63, 60, 61 for implementing an automatic scan tuning mode, the device 50, 52, 60, 61, 63 having a second manual actuator 63a and at least first and second positions. A switch device 63 is provided, by which the switch device 63 generates and maintains the scan enable signal in response to an initial manual movement of the second manual operator from the first position to the second position; Devices implementing scan tuning mode include:
coupled to said receiving devices 42-47, 55, 60, 61 for automatically generating a first inhibit signal as part of an automatic scan tuning mode while said automatic scanning tuning mode is present and said receiving device is tuned; While the receiving device is receiving an incoming channel signal of a channel, in response to this reception, temporarily prohibiting other channels from being automatically tuned, and after and in response to the completion of reception of the channel signal. a multi-channel communications system for operating on a plurality of scheduled channels, the system comprising a device 50, 52 for automatically restoring the automatic scan tuning sequence when coupled to the receiving device and corresponding to a selected channel to which the receiving device is tuned; a transmitting device 12 for selectively transmitting a signal to a selected channel and generating a second inhibit signal responsive to a transmitting operation for transmitting a signal to terminate the automatic scan tuning mode;
, 26, 40, 28, 197, the automatic scanning tuning mode is terminated by a second inhibit signal which terminates the scanning operation enable signal, and the automatic scanning tuning mode is terminated by moving the second manual actuator of the switching device again. preventing the next consecutive automatic tuning in the automatic scanning tuning mode until a scanning operation enable signal is generated again; the automatic scanning tuning mode is terminated by sending the signal; and the automatic scanning tuning is prevented from automatically resuming thereafter. A multi-channel communication device characterized by: 2. A manual switching device 55 is provided having a first manual actuator 55a coupled to the receiving device to manually select the channel to which it is tuned, the manual switching device also having first and second positions, and an automatic switching device. When tuning is prohibited by the first prohibition signal, the operating element is moved to one of the first and second positions, a new channel is selected by the receiving devices 42 to 47, 60, and 61, and the receiving device automatically The multi-channel communication device according to claim 1, characterized in that the tuning sequence is restored. 3. a first manual actuator 55a coupled to the receiving device and a manual switch device 55 having a plurality of mechanical positions for manually selecting the channel to which the receiving device is tuned;
Further, the automatic tuning devices 63, 60, and 61 are appropriately configured so that when the automatic tuning devices are ready for operation, their operation is independent of the mechanical position of the first manual operating element 55a of the manual switch device 55. A multi-channel communication device according to claim 1, characterized in that the multi-channel communication device is configured as follows. 4 A device 6 coupled to the switch device 63 of the automatic tuning device for visually indicating the presence or absence of the scanning enable signal by means of illumination.
4. A multi-channel communication device as claimed in claim 1, further comprising: 4 for visually indicating an automatic scan tuning mode of operation of the communication device. 5. A patent claim characterized in that the second actuator 63a of the switch device 63 is always positioned at the first position, and the second actuator 63a is held at the second position by a constant manual pressing force. The multi-channel communication device according to scope 4. 6. A bistable circuit device 190 is provided in the switch device 63, and the bistable circuit device alternately generates the scanning operation enable signal in response to each movement of the second operating element 63a to the second position. 6. The multichannel communication device according to claim 5, wherein the multichannel communication device is configured to terminate the communication. 7. The multi-channel communication device according to claim 6, characterized in that a bistable circuit device (190) terminates the scanning enable signal in response to a transmission signal from the transmitting device. 8. An on-off switch 16 for supplying operating power is provided, and after the transmitting device receives operating power from the on-off switch 16 by the switching device 63, the actuator 63a of the switching device is initially in the second position. 7. The multi-channel communication device according to claim 6, wherein the multi-channel communication device generates a continuous scanning operation enable signal in response to movement.