JPS6346988Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an operating circuit for a keep relay that turns on and off a load by changing the direction of current based on the output of a sensor that detects environmental conditions such as light and temperature.

Conventionally, this type of operation circuit has been constructed with an auxiliary contact (d) of a load keep relay that switches between diodes (I) and (b) connected in parallel in opposite directions to change the direction of current, a coil (ho) of this keep relay, and a diode (a) connected in parallel in opposite directions to change the direction of current. The auxiliary contact of the keep relay, which operates the load keep relay, is connected in series with the power source, and changes in environmental conditions such as light and temperature are detected by a sensor. The output of this sensor opens and closes the operating keep relay and correspondingly opens and closes the load keep relay, thereby changing the direction of the current and turning the load on and off. Therefore, in addition to the load keep relay that turns the load on and off, a keep relay is required to operate the load keep relay, and it is not possible to directly drive the load keep relay with the sensor output. The drawback was that the circuit was complicated.

This idea was developed with the above in mind, and its purpose is to directly drive the keep relay that turns the load on and off using the output of the sensor, simplify the circuit, and reduce power consumption. An object of the present invention is to provide an operation circuit for a keep relay that is economical.

Below, an example of this invention is applied to a photoelectric automatic flasher, and changes in light are detected as changes in resistance.
This will be explained based on FIG. 2 in which a variable resistance element A is used as a sensor such as a Cds cell. E is an AC power supply, and the keep relay Rk switches the coil L of the keep relay Rk and diodes D ₁ and D ₂ connected in parallel in opposite directions to change the direction of the current and maintain this state even when the current stops flowing. , the auxiliary contact S, the variable resistance element A, and the bias resistor _r1 connected to both ends of the variable resistance element A.
A bias circuit X consisting of _r2 is connected in series. Tr ₁ is a PNP type switching transistor, and the current i ₁ is in the same direction as the diode D ₁ .
A corresponding diode D ₃ is connected to its collector so as to allow a current to flow therethrough, and is arranged in parallel at both ends of the bias circuit X, and its base is connected to the junction between the variable resistance element A and the bias resistor r ₁ . Tr ₂ is an NPN type switching transistor, and a corresponding diode D ₄ is connected to the emitter so that a current i ₂ flows in the same direction as the diode D ₂ , and the bias circuit X is connected to the switching transistor.
The transistors Tr ₁ and Tr 2 are connected in parallel to both ends, and their bases are connected to the junction between the variable resistance element A and the bias resistor r ₂ , and the bases of the transistors Tr ₁ and Tr ₂ are connected via the variable resistance element A. There is. More transistors
Connect the emitter of Tr ₂ to variable resistance element A and bias resistor.
It is connected to the junction with r ₁ . Therefore, at night, when there is no light on the resistance change element A and the resistance value of the resistance change element A is large, the auxiliary contact S closes the diode _D1 , the switching contact M closes, and the load Z such as an outdoor light is turned on. It's summery. Next, when the sun rises and the resistance change element A is exposed to light and its resistance value decreases, the base voltage of the transistor Tr ₁ comes to be determined almost solely by the bias resistors r ₁ and r ₂ . Then transistor Tr ₁ conducts and current i ₁ becomes diode
The keep relay Rk is inverted through D ₃ and D ₁ .
Then, the switching contact M is opened and the load Z is turned off, and the auxiliary contact S closes the diode _D2 so that the current _i1 does not flow, thereby cutting off the current after reversal, thereby reducing power consumption. Keep relay Rk maintains this state. The diode _D4 bypasses the current _i0 flowing in this state, thereby preventing the transistor _Tr2 from becoming conductive due to the variable resistance element A and the bias resistor _r1 . Further, when night falls and the resistance value of the variable resistance element A increases, the base voltage of the transistor _Tr1 decreases. Then, the transistor Tr ₂ becomes conductive and the current i ₂ passes through the diodes D ₂ and D ₂ to invert the keep relay Rk. Then, the switching contact M is closed and the load Z is turned on, and the auxiliary contact S closes the diode _D1 so that the current _i2 no longer flows. Note that temperature control can be performed simply by changing the resistance change element A to, for example, a thermistor, and any resistance change element A may be used.

As described above, this device uses a transistor Tr ₁ which shares a bias circuit X and has a diode D ₃ connected to the diode D ₁ and the corresponding diode D 3 connected to both ends thereof, and a transistor Tr ₂ which has a diode D ₄ which corresponds to the diode D ₂ connected to each other. Since the bases of transistors Tr ₁ and Tr ₂ are connected in parallel via the variable resistance element A, transistors Tr ₁ and Tr ₂ are alternately connected as the resistance value of variable resistance element A changes. Since conduction occurs and currents i ₁ and i ₂ flow in opposite directions, the load Z
The bias circuit X including the variable resistance element A and these transistors Tr ₁ and Tr ₂ can control the load Z without using a keep relay Rk to operate the keep relay Rk in addition to the keep relay Rk that turns on and off the Even if the keep relay Rk is located far away from the position of the keep relay Rk that turns on and off, the keep relay Rk can be directly driven by the output of the variable resistance element A using the AC power supply path E, and only one keep relay needs to be used. A keep relay operating circuit can be obtained whose circuit is simplified and power consumption can be reduced.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing a conventional example of this invention, Figure 2 is a circuit diagram showing a conventional example of this invention.
The figure is a circuit diagram showing an embodiment of this invention. Diodes D ₁ , D ₂ , D ₃ , D ₄ , transistors
Tr ₁ , Tr ₂ , bias resistance r ₁ , r ₂ , keep relay
Rk, auxiliary contact S, variable resistance element A, bias circuit X, AC power supply E.

Claims (1)

[Scope of utility model registration request] It consists of a switching contact M, a coil L, and an auxiliary contact S, and includes a keep relay Rk in which one end of the coil L is connected to a common contact of the auxiliary contact S, and the other end of the coil L is connected to one end of the AC power source E. The cathode of the first diode D1 is connected to the first switching contact of the auxiliary contact S, and _the anode of the second diode _D2 is connected to the second switching contact of the auxiliary contact S. The anode of the diode _D1 and the cathode of the second diode _D2 are commonly connected _, and _a bias circuit One end of the second bias resistor r ₂ is connected to the common connection point of the first and second diodes D ₁ and D ₂ , and one end of the first bias resistor r ₁ is connected to the other end of the AC power source E. It is connected between the common connection point of the first and second diodes D ₁ and D ₂ and the other end of the AC power supply E so that the emitter-collector circuit of the PNP type transistor Tr ₁ and the PNP
The series circuit with the third diode D ₃ whose anode is connected to the collector of the type transistor Tr ₁ is shown above.
The emitter of the PNP transistor Tr ₁ is on the other end side of the AC power supply E, and the cathode of the third diode D ₃ is on the common connection point side of the first and second diodes D ₁ and D ₂ . An NPN transistor Tr ₂ is connected between the common connection point of the first and second diodes D ₁ and D ₂ and the other end of the AC power supply E.
A fourth transistor whose anode is connected to the collector-emitter circuit of and the emitter of the NPN transistor Tr ₂ mentioned above.
A series circuit consisting of a diode _D4 is connected to the fourth
The cathode of the diode _D4 is connected to the other end of the AC power supply E, and the collector of the NPN transistor _Tr2 is connected to the common connection point of the first and second diodes _D1 and _D2 . , connect the connection point between the first bias resistor r ₁ and the variable resistance element A to the base of the PNP transistor Tr ₁ and the
Connect to the emitter of NPN transistor Tr ₂ ,
The second bias resistor _r2 and the variable resistance element A
An operating circuit for a keep relay, characterized in that a connection point with the NPN transistor Tr ₂ is connected to the base of the NPN transistor Tr 2.