JPS631485Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides for a device including a transmitting part and a receiving part integrally, such as a transmitter/receiver or a transceiver.
Regarding the improvement of the above-mentioned transmitting/receiving switching device that connects the transmitter and receiver to the antenna using a switch, direct current flows through the switch during reception, and contact failure of the switch during reception when only a minute current flows. It is designed to prevent this.

In such a conventional transmitting/receiving device, as shown in FIG. 1, a transmitting section TR and a receiving section RE are respectively connected to a transmitting contact T1 and a receiving contact T2 of a switching device RL consisting of a relay or a switch, etc. , the common terminal CO of the switch RL is connected to the antenna A. Then, the switching piece of the switching device RL is
By being switched and connected to the transmitting contact T1 or the receiving contact T2, the purpose is changed to the transmitting state or the receiving state.

However, while a relatively large current flows through RL when switching during transmission, only a small current flows during reception, so an insulating film such as an oxide film tends to adhere to the reception contact T2, which may cause damage. When switching to reception state,
A poor contact occurs between the switching piece and the receiving contact T2, causing a serious inconvenience in which normal receiving operation cannot be performed.

The present invention takes into consideration the drawbacks of the conventional art and solves the drawbacks of the conventional art by allowing direct current to flow through the switch only during reception.
Next, the transmitting/receiving switching device of the present invention will be explained in detail with reference to FIG. 2 showing one embodiment thereof.

In the figure, the same symbols are attached to the same or equivalent parts as those in Figure 1, and B is the DC power supply connected to the receiving contact T2 of the switch RL via the load resistor R1. , C1 and C2 are DC blocking capacitors inserted and connected between the antenna A and the common terminal CO of the switch RL, respectively, and R2 is a resistor.

In the embodiment device configured as described above, when the switching piece of the switching device RL is switched and connected to the reception contact T2, a discharge circuit of the DC power source B is formed, and the switching piece of the switching device RL is connected from the DC power source B to the resistor R1. Since a direct current flows through the resistor R2 and the receiving contact T2, even if an insulating film is formed on the receiving contact T2, the insulating film is destroyed by the direct current, and a normal receiving operation can always be performed. In addition, the DC current is cut off by the two capacitors C1 and C2, and the resistance values of the resistors R1 and R2 are sufficiently large compared to the impedance of the circuit, so that power loss can be ignored. has no effect on weak received signals.

Further, in the embodiment described above, the direct current flowing through the switch RL is grounded, but it is of course possible to connect and use the direct current to other devices that require direct current. Further, instead of flowing a DC current every time a signal is received, the DC power source B may be connected to the receiving contact point in a freely disconnectable manner as required.

As mentioned above, according to the transmitting/receiving switching device of the present invention,
Since the configuration is such that a direct current is passed through the switch during reception, even if an insulating film adheres to the receiving contacts, it can be destroyed by the direct current, and the receiving operation can be performed stably.

[Brief explanation of the drawing]

Figure 1 is a wiring diagram of a conventional transmitting/receiving switching device;
The figure is a wiring diagram of an embodiment of the transmitting/receiving switching device of the present invention. TR...Transmitter, RE...Receiver, RL...Switcher, T2...Receiving contact, CO...Common terminal, B
...DC power supply, A...antenna.

Claims (1)

[Scope of utility model registration request] In a transmitting/receiving switching device that switches and connects a transmitting section and a receiving section to an antenna using a switching device such as a relay,
A transmitting/receiving switching device characterized in that a DC power source is connected to a receiving contact of the switching device to which a receiving section is connected, and a DC current is superimposed upon reception.