JPS6318365B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for switching signal paths between added circuitry and existing circuitry.

As shown in FIG. 1a, a front stage circuit 1, a rear stage circuit 2
In a circuit configuration in which the circuits are connected in series, an additional circuit 3 is added between the front-stage circuit 1 and the rear-stage circuit 2 as shown in FIG. 1b in order to add functions or change the characteristics of the output signal. may be inserted.
For example, in a circuit that uses a low-pass circuit as the front-stage circuit and a gain circuit as the rear-stage circuit to extract, amplify, and output a low-frequency signal, a high-pass circuit is added as an additional circuit between the front-stage circuit and the rear-stage circuit. In some cases, the characteristics of the entire circuit are bandpass characteristics, and a band signal is extracted, amplified, and output. On the other hand, there is a case where the circuit normally has a circuit configuration as shown in FIG. 1B, and when necessary, it may be configured such that the additional circuit 3 is not used as shown in FIG. 1A.

When inserting the additional circuit 3 in such a circuit configuration, in order to connect the output of the preceding circuit 1 to the input of the additional circuit 3, and the output of the additional circuit 3 to the input of the subsequent circuit 2, Normally, the connection from the output of the front-stage circuit 1 to the input to the rear-stage circuit 2, which was made before insertion, must be disconnected. The following methods have generally been used to change this connection. As shown in FIG. The output signal route was changed. There is also a method of using a switching terminal such as a strap terminal instead of the switch 4. Furthermore, when the additional circuit 3 is not required as shown in FIG. 1d, a method has been adopted in which a dummy circuit unit 6 for the sole purpose of connection is inserted in place of the additional circuit 3.

However, these methods require accompanying operations such as switching a switch, changing the strap terminal, or inserting a dummy circuit when the additional circuit unit 5 is inserted or removed. Moreover, if this accompanying operation is performed incorrectly or a dummy circuit is incorrectly inserted, the intended operation may not be performed, and the elements constituting the circuit may be damaged.

Furthermore, in circuits operated by minute currents, consideration must be given to the contact resistance of the contacts and the contact current of the switch or strap terminal, as well as the selection of contact materials.

In order to eliminate these drawbacks, the present invention is designed to switch the signal path between the added circuit and the existing circuit without performing any additional operations when a circuit unit is inserted or removed.

FIG. 2 shows an embodiment of the present invention, in which 1 is a front-stage circuit (first circuit), 2 is a rear-stage circuit (second circuit),
3 is an additional circuit (third circuit), 5 is an additional circuit unit, 7 is a switch circuit, 8 is a control signal input terminal of the switch circuit, and 9 is a pull-up resistor.

The control signal input terminal 8 is connected to the terminal section 11,
At the same time, it is connected to a +V power supply via a resistor 9. The output terminal of the pre-stage circuit 1 and the signal input terminal of the switch circuit 7 are always connected, and at the same time the terminal section 12
It is directly connected to The output end of the switch circuit 7 is connected to the signal input end of the subsequent stage circuit 2, and is also directly connected to the terminal section 13.

The unit 5 is incorporated into a printed circuit board or the like, and has terminal portions 14, 15, 16, and 17. The terminal portions 14 and 15 are directly connected inside the unit, and one terminal portion 14 is configured to be connected to the -V power source and the other terminal portion 15 is opposite to the terminal portion 11, respectively. Additional circuit 3
A signal input end of the terminal is directly connected to a terminal portion 16, and the terminal portion 16 is opposed to the terminal portion 12.

Further, the output end of the additional circuit 3 is directly connected to a terminal portion 17, and the terminal portion 17 is configured to face the terminal portion 13.

Each terminal part of the unit and terminal parts 10, 11, 1
2 and 13 are connected by connectors.

This operation is performed when the switch circuit 7 whose power supply is +V voltage and -V voltage with a width greater than the maximum amplitude of the output signal of the pre-stage circuit 1 is connected to the output of the pre-stage circuit 1, and the additional circuit unit 5 is not connected. Since the control terminal 8 of the switch circuit 7 is not connected to the -V voltage and is pulled up to the +V voltage by the pull-up resistor 9, the switch circuit 7 becomes conductive, and the output signal of the previous stage circuit 1 is connected to the switch circuit 7. It is input to the subsequent stage circuit 2 through.

At this time, since the additional circuit unit 5 is not connected, the output of the preceding stage circuit 1 is not connected to the input of the additional circuit 3, but is only connected to the input of the switch circuit 7.

Next, when the additional circuit unit 5 is connected, the control terminal 8 of the switch circuit 7 is connected to the -V voltage, the switch circuit 7 is turned off, and the previous stage circuit 1
The output signal is not applied to the input of the subsequent stage circuit 2, but is applied to the input of the additional circuit 3. The output signal of the additional circuit 3 is then applied to the input of the subsequent circuit 2.

By inserting and removing the additional circuit unit 5, the voltage applied to the control terminal 8 of the switch circuit 7 is reversed, thereby controlling the on/off state of the switch circuit 7, and switching the signal path between the front stage circuit 1 and the rear stage circuit 2. Therefore, it is not necessary to change the operation switch for changing the signal path or change the strap due to the insertion and removal of the additional circuit unit 5 mentioned above. Furthermore, since mechanical contacts such as switches and strap terminals are not used, there is no need to consider contact current or select contact materials even in circuits that handle minute currents.

As explained above, according to the present invention, there is no need to perform operations associated with inserting and removing additional circuit units, so that malfunctions of the circuit and damage to elements due to incorrect operations do not occur, and the mounting area occupies a relatively large area. There is no need to mount switches or strap terminals.

Furthermore, this device can be used not only for analog signal circuits but also for digital signal circuits, and its application range is wide. In the switch circuit, an analog switch can be used to control the passage of analog signals, and a digital logic element can be used to control the passage of digital signals. It is especially suitable when using an option unit.

[Brief explanation of the drawing]

FIGS. 1a, b, c, and d are conventional circuit configuration diagrams, and FIG. 2 is a block diagram of the present invention. 1: Pre-stage circuit, 2: Post-stage circuit, 3: Additional circuit,
4: Switch, 5: Additional circuit unit, 6: Dummy circuit unit, 7: Switch circuit, 8: Switch circuit control terminal, 9: Pull-up resistor, 10~
17: Terminal part.

Claims (1)

[Claims] 1 A third circuit 3 having a predetermined function is interposed between the first circuit 1 and the second circuit 2 connected in series, and the output signal of the first circuit is transmitted to the second circuit 2. In a device that switches and utilizes a signal by inputting it directly to the second circuit or inputting it to the second circuit via a third circuit, the third circuit is disposed within the unit 5, and the third circuit is provided in the unit 5. At least 4 terminal parts 1
4, 15, 16, and 17, the terminal portion 14 and the terminal portion 15 are connected within the unit, and the terminal portion 14 is connected to -V.
The terminal section 10 connected to the power supply and the terminal section 15 are located so as to be connected to the terminal section 11 connected to the +V power supply via a resistor, respectively, and the terminal section 16 is connected to the input end of the third circuit. The terminal portion 17 is connected to the output end of the third circuit and is connected to the input end of the second circuit. A switch circuit 7 is disposed at a position where it is connected to the terminal section 13 to be connected, and is used for switching the signal, and the signal input terminal of the switch circuit is connected to the first terminal.
connected to the output end of the circuit and the terminal section 12,
The output end is the input end of the second circuit and the terminal section 13
and has a control signal input terminal section 8 of the switch circuit, and the control signal input terminal section is connected to the +V power supply via the resistor and at the same time connected to the terminal section 11. The switch circuit 7 operates so that when the control signal input terminal section 8 is connected to the -V power supply, it is turned off, and when it is connected to the +V power supply through the resistor 9, it is turned on. A signal switching device characterized by having a structure in which the terminals can be inserted and removed using a connector that connects correspondingly.