JPH07307129A - Timer device - Google Patents

Abstract

PURPOSE:To reduce a decrease in applied DC voltage at the time of operation of an output relay so as to prevent erroneous resetting of a time interval circuit by applying the DC voltages, which are obtained by rectifying a positive and a negative half-wave of an AC voltage, to the output relay and the time interval circuit, respectively. CONSTITUTION:A positive half-wave of an AC voltage of an AC power source 2 is rectified by a diode 4B. The rectified DC voltage is supplied to a series circuit consisting of an output relay 10 and an NPN transistor(TR) 9A. Meanwhile, a DC voltage obtained by rectifying a negative half-wave of a voltage of the power source 2 by a diode 4A is supplied to a time interval circuit 8. The relay 10 is operated via the transistor 9A, which is turned on by the circuit 8 after a lapse of a predetermined time. With such constitution as to supply the voltages to the relay and the time circuit, respectively, it is possible to reduce a decrease in applied voltage even at the time of operation of the relay as to prevent erroneous resetting of the time interval circuit 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timer device which is driven by an AC power source and whose output relay operates in response to an output signal of a time circuit.

[0002]

2. Description of the Related Art FIG. 3 is a circuit diagram showing a conventional example of this type of timer device. In FIG. 3, the timer device includes terminals U and V connected to an AC power supply 2 via a switch 1, an anode thereof connected to a terminal U, and a cathode thereof connected to a terminal V via a current limiting resistor 5 and a capacitor 7 connected in series. , A Zener diode 6 connected in parallel with the capacitor 7, an output relay 10 connected between both terminals of the capacitor 7, and an N as a switching element.
A series circuit composed of a collector and an emitter of the PN transistor 9A, a capacitor 11 connected in parallel to the output relay 10 and both terminals of the capacitor 7, and a time limit when the output terminal is connected to the base of the NPN transistor 9A. And the circuit 8. The time limit circuit 8 starts clocking when the DC voltage is turned on and is reset when the DC voltage is turned off.

The operation of this timer device is as follows.
First, when the switch 1 is closed, the AC voltage of the AC power supply 2 is half-wave rectified by the diode 4, and the rectified DC voltage charges the capacitor 7 via the current limiting resistor 5,
The direct-current voltage between the two terminals rises to the voltage of the Zener diode 6. A DC voltage between both terminals of the capacitor 7 is applied to the time limit circuit 8, and when the DC voltage becomes equal to or higher than a predetermined value, the time limit circuit 8 starts timing, and after the set time limit,
A signal is output from the output terminal to the gate of the NPN transistor 9A. The NPN transistor 9A is turned on by this output signal, and the output relay 10 operates. Next, when the switch 1 is opened, the output relay 10 is released, and at the same time, the time circuit 8 is reset to return to the original state. The capacitor 11 is for absorbing the electromagnetic energy emitted from the coil of the output relay 10 when the switch 9 is opened.

[0004]

In the above-described timer device, the AC voltage of the AC power supply is half-wave rectified by the diode 4, and the capacitor 7 is charged with this rectified DC voltage.
Moreover, the Zener diode 6 is connected in parallel to this capacitor 7 so that the DC voltage between both terminals of this capacitor 7 applied to the time circuit 8 is made as constant as possible, but when the output relay 10 is operating, This output relay 10
Since the load current is large, the DC voltage across the terminals of the capacitor 7 applied to the time limit circuit 8 drops, which may cause malfunction such as resetting of the time limit circuit 8.
This is particularly remarkable when the impedance of the AC power supply or the wiring between the AC power supply and the timer device is large.

An object of the present invention is to provide a timer device in which a decrease in the DC voltage applied to the time circuit is reduced when the output relay operates.

[0006]

In order to achieve the above-mentioned object, the timer device of the present invention is a series circuit comprising an output relay to which a DC voltage obtained by rectifying a half wave of one pole of an AC voltage and a switching element are applied. And, a DC voltage obtained by rectifying the half wave of the other pole of the AC voltage is applied, the clocking is started by turning on the DC voltage, and reset by turning off the DC voltage,
And a time-limit circuit for controlling on / off of the switching element of the series circuit by the output signal. The switching element is composed of, for example, an NPN transistor or a PNP transistor.

[0007]

In the timer device of the present invention, the output relay rectifies a unipolar half-wave of the AC voltage of the AC power source into a DC voltage, and the time circuit rectifies the other-polarity half-wave into a DC voltage. When the output relay is operated by turning on the switching element composed of, for example, an NPN transistor or a PNP transistor, the DC voltage applied to the time circuit is less likely to decrease.

[0008]

1 is a circuit diagram showing an embodiment of a timer device of the present invention. In FIG. 1, the timer device is a switch 1
Terminals U and V connected to the AC power supply 2 via
A cathode / anode of a diode 4B and an anode / cathode of a diode 4A connected in series between V,
A series circuit including an output relay 10 connected between the terminal U and the anode of the diode 4A and a collector / emitter of an NPN transistor 9A as a switching element, and a capacitor 11 connected in parallel to the output relay 10.
A current limiting resistor 5 and a capacitor 7 connected in series between the terminal V and the anode of the diode 4B;
A Zener diode 6 connected in parallel with the capacitor 7, and a time circuit 8 connected between both terminals of the capacitor 7 and having its output terminal connected to the base of the NPN transistor 9A.

The operation of this timer device is as follows.
First, when the switch 1 is closed, the positive half wave of the AC voltage of the AC power supply 2 is rectified by the diode 4A, and the DC voltage rectified by this positive half wave is applied to the series circuit of the output relay 10 and the NPN transistor 9A. It The negative half-wave is rectified by the diode 4B, the DC voltage rectified by the negative half-wave charges the capacitor 7 through the current limiting resistor 5, and the DC voltage between both terminals of the capacitor 7 is zener diode. The voltage rises to 6. A direct current voltage between both terminals of the capacitor 7 is applied to the time limit circuit 8, and when the direct current voltage exceeds a predetermined value, the time limit circuit 8 starts timing, and after the set time limit, the gate of the NPN transistor 9A is output from the output terminal. Output a signal to. The NPN transistor 9A is turned on by this output signal, and the output relay 10 operates. Next, when the switch 1 is opened, the output relay 10 is released, and at the same time, the time circuit 8 is reset to return to the original state. It should be noted that the capacitor 11 is used when the switch 9 is opened and the output relay 1
It is for absorbing the electromagnetic energy emitted from the 0 coil.

In this timer device, a DC voltage obtained by rectifying a positive half-wave of the AC voltage of the AC power supply 2 is output to the output relay 10, and a DC voltage obtained by rectifying the negative half-wave is output to the time circuit 8. Since the signals are applied in a divided manner, when the NPN transistor 9A is turned on and the output relay 10 is operated, the DC voltage applied to the time limit circuit 8 is less likely to drop, and malfunctions such as resetting of the time limit circuit 8 are prevented. It

FIG. 2 is a circuit diagram showing another embodiment of the timer device of the present invention. The embodiment shown in FIG. 2 is different from the embodiment shown in FIG. 1 in that an NP as a switching element is used.
The point is that a PNP transistor 9B is used instead of the N transistor 9A, and the connection of each electronic component is changed according to the polarity of the PNP transistor 9B. The operation and function of this timer device are the same as in FIG.

[0012]

In the timer device of the present invention, a decrease in the DC voltage applied to the time circuit when the output relay is operated is small, and malfunctions such as erroneous reset of the time circuit are prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a timer device of the present invention.

FIG. 2 is a circuit diagram showing another embodiment of the timer device of the present invention.

FIG. 3 is a circuit diagram showing an example of a conventional timer device.

[Explanation of symbols]

 2 AC power supply 4A diode 4B diode 8 time circuit 9A NPN transistor (switching element) 9B PNP transistor (switching element) 10 output relay

Claims (3)

[Claims] 1. A series circuit comprising an output relay and a switching element to which a DC voltage obtained by rectifying a half-wave of one pole of an AC voltage is applied, and a DC voltage obtained by rectifying a half-wave of the other pole of the AC voltage is applied. A timer device, comprising: a time circuit which starts time measurement when the DC voltage is turned on, is reset when the DC voltage is turned off, and controls on / off of a switching element of the series circuit by an output signal thereof. 2. The timer device according to claim 1, wherein the switching element is an NPN transistor. 3. The timer device according to claim 1, wherein the switching element is a PNP transistor.