JPS58179043A - Telephone set - Google Patents

Abstract

PURPOSE:To obtain a telephone set containing a tone ringer with which the number of component parts can be decreased, by using a tone ringer circuit and a speech sending amplifying circuit in common. CONSTITUTION:When a telephone is hooked on, hook switches HS1-HS4 are set in a state as shown in the diagram. A positive feedback path consisting of the switch HS3, a resistance R3 and R10 is provided to an amplifier 1. When a call signal arrives, a rectifying circuit 5 applies the DC voltage obtained rectifying the call signal to a speech sending amplifying circuit consisting of an output transistor 8 and the amplifier 1. The amplifier 1 has oscillations with the above-mentioned positive feedback path, and the output of oscillation is delivered to a speaker SP via the transistor 8 to inform a call. When a handset is hooked off, the positive feedback path is cut. Thus both the speeth sending amplifying circuit and a receiving amplifier 9 work in exactly the same way as conventional with a DC current given from a line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Description of Technical Field] The present invention relates to a telephone with a tone ringer, and particularly to its circuit configuration.

[Description of prior art]

An example of a conventional telephone with a tone ringer is shown in FIG. A transmitting amplifier circuit 2 including a transmitting operational amplifier 1 and a tone ringer circuit 3 are each provided independently, and when a call is made, a calling signal is sent to a hook switch H8I, a capacitor C1, and a tone ringer circuit 3.
The signal is rectified and smoothed by a diode bridge 5 and a capacitor C2 via a resistor R1, and is used as a power source to operate an oscillator 6.

The output is applied to the speaker driving transistor 7 to drive the speaker BP. Also, when talking, hook switch H8
1 is switched, and the signal from the microphone M is sent to the line by the operational amplifier 1 for voice transmission and the output transistor 8.

In Figure 1, 9 is a receiving amplifier, 10 u diode bridge, C, 04 is a capacitor, R2-R7 is a resistor,
A ZB Fi sidetone balancing network and an RFi handset are shown, respectively.

As described above, the conventional telephone with a tone ringer has a drawback that the transmitting amplifier circuit and the tone ringer circuit are each provided as independent circuits, and there are many parts.

[Explanation of purpose]

The present invention aims to improve this point, and aims to provide a telephone with a tone ringer that can serve as both a tone ringer circuit and a transmitting amplifier circuit, thereby reducing the number of parts.

[Summary of the invention]

The present invention is a first hook switch group that includes a speaker, a positive feedback resistor, and first and second hook switches in a common round circuit for a transmitting amplifier and a tone ringer circuit, and short-circuits the speaker during a call. Then, the speaker is activated, one end of the positive feedback resistor is connected to the output terminal of the transmitting amplifier, and the other end is connected to the input of the transmitting amplifier using a hook switch, and the speaker is operated as an oscillator. It is characterized in that it is controlled to operate as a tone ringer circuit when a call is made.

[Explanation based on examples]

An embodiment of the present invention will be described based on the drawings.

FIG. 2 is a block diagram of main parts of an embodiment of the present invention.

In comparison with the conventional example shown in FIG. 1, the tone ringer circuit 3 is omitted, a speaker BP is connected to the collector of the output transistor 8, a hook switch HBz is connected in parallel to this, and the transmitting operational amplifier 1 is connected to the collector of the output transistor 8. The feature is that a series circuit consisting of a positive feedback resistor R1 and a hook switch [8g] is inserted between the output terminal and the positive phase input terminal, and a hook switch HB4 is further provided.

Other points are similar to the conventional example shown in FIG. 1, and the same reference numerals indicate the same parts.

As described above, with the circuit configuration 1, the characteristic operation tl of the present invention is
! I will clarify. Now, when the telephone is on standby, that is, when a call is made, the hook switches [89 to HB4 are set to 1KT as shown in FIG.
oru. One end of the operational amplifier 1 for transmitting, which operates as a transmitting amplifier during a call, is connected to the output of 1, and the other end is connected to the non-inverting input of the operational amplifier for transmitting 1 by means of a hook switch H8M. It is connected. Furthermore, a speaker SP is inserted into the collector of the output transistor 8 which outputs a transmission signal to the line during a call by breaking the hook switch HE12i. In addition, the receiver amplifier 9#
It is disconnected by i-box switch HB2.

In this state, the call signal is connected to capacitor c1 and resistor R.
1, the signal is rectified by a diode bridge 5, and is supplied to a speaker sp. Furthermore, the call signal is transmitted by the resistor R5.
, and is smoothed by the capacitor OaK and supplies power to the operational amplifier 1 for transmission.

This is K), more calculations for transmitting during calls @W! The output transistor 8t-1 and the output transistor 8t-1 can each be operated as an oscillator and a speaker driving transistor when called. During a call, the transmitting amplifier @1III, the output transistor 8, and the receiving amplifier 9 are connected to the hook switch H81.
~H84 is switched in the opposite direction to the position shown in Figure 2 and 'J?
In addition, a transmitter circuit similar to the conventional example shown in No. 111 is constructed.

[Explanation of effects]

As explained above, according to the present invention, the transmitting amplifier is operated as an oscillator and the output transistor is operated as a speaker drive by switching the hook switch depending on whether a call is made or a call is made. Therefore, parts can be shared, and the number of parts can be reduced.

[Brief explanation of drawings]

FIG. 1 shows the main block configuration wJ of a conventional example. FIG. 2 is a diagram showing the configuration of a main part of a plotter according to an embodiment of the present invention. 1-Operation amplifier for transmitting voice, 2-Amplifying circuit for transmitting voice, 3-Tone ringer circuit, 5.10--Diode bridge,
6--Oscillator, 7--Speaker driving transistor,
8 - Output transistor, 9 - Receiving amplifier. (,5 pa・r

Claims (1)

[Claims] (1) A telephone equipped with a transmitting operational amplifier having a microphone connected to its input, and an output transistor connected so that the output of the transmitting operational amplifier is guided to its base and the collector output is sent out to a line. a power supply circuit that rectifies the calling signal current arriving at the line and supplies it as a power supply current to the transmitting operational amplifier; a speaker connected to the collector circuit of the output transistor; and a power supply circuit connected in parallel to the speaker. a series circuit of a positive feedback resistor and a second hook switch connected between the output terminal and the positive phase input terminal of the transmitting operational amplifier; The switch is configured to be open during standby and closed during a call, and the second hook switch is configured to be closed during standby and open during a call.