JPS6040027Y2 - signal distribution circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal distribution circuit, and more particularly to a circuit that distributes a signal from a circuit comprising a low impedance signal source and a load circuit to a high impedance load circuit.

Conventionally, when extracting a signal (or part of a signal) from a low-impedance signal source connected to a load circuit, the impedance of the signal source and the impedance of the load circuit must be sufficiently higher to avoid affecting the signal voltage sent to the load circuit. It uses a signal distribution circuit that connects a high impedance circuit in parallel to the signal source.

FIG. 1 is a diagram showing a conventional example of such a signal distribution circuit.

The signal voltage of the signal source 1 is divided into two by the signal source impedance 11 (impedance Z1) and the load impedance 21 and the impedance 4, and the load circuit 2 is given half the signal voltage of the signal source 1.

In addition, since the load impedance 31 (impedance Z2) is set to be sufficiently larger than the signal source impedance 11 or the load impedance 21 in the load circuit 3, it is possible to apply it to the load circuit 2 without affecting the signal voltage. Equivalent signal voltages are extracted.

However, as shown in FIG. 1, the signal source 1 and the load circuit 2
In a circuit that connects and separates using relay 5,
When the load circuit 2 is separated from the signal source 1, the signal source 1 and the load circuit 3 are directly connected only through the signal source impedance 11. Therefore, since the impedance 4 is sufficiently large compared to the impedance Z1, the signal source 1 signal voltage, which is twice the signal voltage when load circuit 2 is connected, is applied to load circuit 3. This has the disadvantage that the distribution signal voltage to the load circuit 3 fluctuates.

In order to eliminate this drawback, a circuit shown in FIG. 2 has been considered.

A relay 5' with a transfer contact is used instead of the relay 5 in FIG. is terminated, and the signal voltage applied to the load circuit 3 is kept constant regardless of whether the load circuit 2 is connected or disconnected.

However, even in this circuit, the load circuit 2 is separated from the signal source 1 while the contact a of the relay 5' moves from contact to contact C, so the signal voltage applied to the load circuit 3 increases during that time. However, the condition that the signal voltage taken out to the load circuit 3 is always constant regardless of whether the load circuit 2 is connected or disconnected is not completely satisfied.

The purpose of the present invention is to eliminate such drawbacks and to develop a signal that can seamlessly distribute a constant signal voltage from a low impedance signal source to a high impedance load circuit regardless of whether the low impedance load circuit is connected or disconnected. It is to provide a distribution circuit.

The present invention will be described in detail below with reference to the drawings.

FIG. 3 is a diagram showing an embodiment of the present invention.

Reference number 4 is a switching circuit, 41 is an impedance equivalent to the load circuit 3, and 42 is a relay that connects and disconnects in conjunction with the relay 5.

When both the relay 5 and the relay 42 are connected, the signal source 1 is connected to the load circuit 2 via the switching circuit 4 and the relay 5, and the signal source impedance 11 and the load impedance 21
Since they are equal, a signal voltage that is half the signal source voltage is applied to the load circuit 2.

Further, the load circuit 3 is connected to the signal source 1 via the relay 42, but since the load impedance 31 is sufficiently large compared to the signal source impedance 11 and the load impedance 21, the load circuit 3 is divided into two by the impedance 114 and the impedance 21z1. A voltage equal to the voltage applied to the load circuit 2 is applied.

Next, when the relay 5 is disconnected and the load circuit 2 is disconnected from the signal source 1, only the load circuit 3 is connected to the signal source 1 via the switching circuit 4, but the relay 42 works in conjunction with the relay 5 to disconnect the load circuit 2 from the signal source 1. Therefore, the load circuit 3 is connected to the signal source 1 via an impedance 41 that is connected between the contacts de of the relay 42 and is equal to the load impedance 31.

Here, since the impedance z2 is set to be sufficiently larger than the impedance B, a voltage divided into two by the impedance 41Z2 and the load impedance 31z2 is applied to the load circuit 3.

Therefore, the same voltage is applied to the load circuit 3 as when the relay 5 and the relay 42 are connected.

Further, the relays 5 and 42 used here may each be separate relays or other switches, but it goes without saying that a single relay with two circuits of contacts may also be used.

FIG. 4 is a diagram showing another embodiment of the present invention.

Signal source 1 and relay 5 in switching circuit 4 in Figure 3
The connection is made through the relay 42, and the operating principle and effect are the same as in FIG.

In the above explanation, impedances 11 and 21 are equal,
Although the impedances 31 and 41 are assumed to be equal, the impedances may be different as long as the voltage distributed to the load circuit 3 is constant regardless of whether the relay 5 is connected or disconnected.

However, unless the impedance of the load circuit 3 is sufficiently larger than the impedance of the load circuit 2, the circuit of the present invention is not necessary.

As explained above, according to the present invention, it is possible to extract a signal voltage equal to that at the termination of the load circuit from a low-impedance signal source regardless of the presence or absence of termination by the load circuit, and to maintain a constant level of signal distribution and signal power supply voltage. It is highly effective if used for constant monitoring.

[Brief explanation of the drawing]

1 and 2 are circuit configuration diagrams of a conventional signal distribution circuit, FIG. 3 is a circuit configuration diagram of a signal distribution circuit according to the present invention, and FIG. 4 is a configuration diagram showing another embodiment of the present invention. . 1... Signal source, 11... Signal source impedance 4.2... Load circuit, 21...
・Load impedance 4.3...High impedance load circuit, 31...Load high impedance Z2.4? 4'...Switching circuit, 41...
...High impedance, 42...Relay,
5... Relay, 6... Terminal impedance Z1.

Claims (1)

[Scope of utility model registration request] from a circuit consisting of a signal source and a first load circuit connected to the signal source via a first switch to a second load circuit having an impedance sufficiently larger than the impedance of the signal source and the first load circuit; In the signal distribution circuit for distributing signals, the first load circuit and the second load circuit are coupled to the signal source in parallel, and a third load circuit is connected between the signal source and the second load circuit. A load circuit is connected, and a second short-circuiting switch that operates in conjunction with the first switch is connected in parallel to the third load circuit, so that the supply voltage from the signal source to the second load circuit is A signal distribution circuit characterized in that the signal is constant regardless of whether the first switch is connected or disconnected.