JPS6112612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a timer device, and relates to a device including two relays that causes a time difference in the return of both relays.

[Conventional technology]

2. Description of the Related Art Conventionally, a configuration shown in FIG. 1 is known as a timer device having two relays of this kind.
In this conventional timer device, when the power applied to the primary side of the transformer 1 is supplied to the instantaneous relay 4 and the timer circuit 5 via the secondary side of the transformer 1, the rectifier 2 and the smoothing capacitor 3, the instantaneous relay 4 operates almost simultaneously with the application of power, while the timer circuit 5 turns on the transistor 7 through the resistor 6 after a set time has elapsed, thereby operating the time-limited relay 8. A configuration is adopted in which a second time limit relay 8 operates.

[Problem that the invention seeks to solve]

In the timer device shown in Fig. 1 above, when the power is turned off, the return voltage of the relay is generally about 10% of the relay coil rated voltage, whereas the return voltage of the timer circuit 5 and transistor 7 is about 40%. Therefore, due to the voltage drop across both ends A and B due to the discharge of the smoothing capacitor 3, there will be a difference in the return levels of the instantaneous relay 4 and the time-limited relay 8, and the time-limited relay 8 will return earlier than the instantaneous relay 4. become.

For example, as shown in FIG. 3, in a sequence device using the timer device T shown in FIG. A push button switch 9 is connected in parallel to the relay contact 4a of the instantaneous relay 4, and the push button switch 9
In order to operate the power supply to the load 28 only once for the set time with one switch operation, the load 28 is connected in parallel with the timer device T. If a circuit is constructed that outputs an output after a set time has elapsed or only for a set time since the push button switch 9 is turned on, a problem will arise if the time limit relay 8 returns earlier than the instantaneous relay 4. That is, when power is applied to the timer device T through the relay contact 8a by turning on the push button switch 9, the timer device T is self-maintained by closing the relay contact 4a, while when the set time elapses, the relay contact 8a The self-holding state must be released by opening the relay contact 4a when the timer device T is powered off. However, when the relay contact 8a is closed again due to the timer device T being powered off, the relay contact 4a is slow to return and remains closed, so the timer device T is again in the self-holding state (fourth (see figure), and if such a phenomenon occurs, it will not be able to function as a timer device.

Furthermore, in a device that uses a timer device to sequence a plurality of loads in a machine tool or the like, it may be necessary to make the timing of the return of one instantaneous drive load earlier than the timing of the return of the other time-limited drive load.

Therefore, in a timer device having two relays, there is a need for a timer device that reliably returns the first relay earlier than the second relay.

The present invention has been made in view of the above points, and is a timer in which the return level of the first relay is changed by a level adjustment circuit so that the first relay returns earlier than the second relay. It provides equipment.

[Means for solving problems]

The timer device of the present invention includes a power supply circuit, a smoothing circuit connected to the power supply circuit, a first relay connected in parallel to the smoothing circuit, and a first relay connected in parallel to the smoothing circuit and receiving power from the smoothing circuit. a timer circuit that operates based on the output and inverts the output signal after a set time elapses; a switching circuit that operates switching based on the output signal from the timer circuit; and a switching circuit that is connected in parallel to the smoothing circuit and performs switching of the switching circuit. and a second relay controlled by the operation, and is characterized in that a level adjustment circuit for changing the return level of the first relay is inserted in series with the first relay. .

[Effect]

In the timer device of the present invention, when power is applied from the power supply circuit, for example, the first relay operates almost simultaneously, the timer circuit is operated, and after the set time has elapsed, the timer device is activated by the output signal from the timer circuit. When the switching circuit turns on, the second
relay is activated. On the other hand, when the power is turned off, the timer circuit turns off according to the discharge characteristics of the smoothing capacitor. At this time, if the level adjustment circuit sets the off level of one relay to a potential higher than the return level of the timer circuit,
The first relay will return earlier than the second relay.

〔Example〕

An embodiment of the present invention will be described with reference to FIG.

A power supply circuit 11 includes a transformer 12 and a rectifier 13 connected to the secondary side of the transformer 12. A smoothing capacitor 14 and a coil of a first relay 15 are connected in parallel to the output end of the rectifier 13.
A level adjustment circuit 16 is inserted in series with the coil. In the level adjustment circuit 16, a series circuit of resistors 17 and 18 and a variable resistor 19 is connected to both ends of the smoothing capacitor 14, and one resistor 1
8 and the variable resistor 19, the base of a transistor 20 whose collector is connected to the (+) side of the smoothing capacitor 14 and whose emitter is connected to the coil of the first relay 15 is connected via a resistor 21. has been configured.

Further, the resistors 17 and 1 of the level adjustment circuit 16
A Zener diode 22 and a capacitor 2 are connected between the midpoint of 8 and the (+) side of the smoothing capacitor 14.
3 and a timer circuit 24 are connected in parallel with each other. This timer circuit 24 includes an oscillation circuit that starts oscillation at an oscillation frequency set by, for example, a time setting dial when power is applied, and divides the oscillation frequency from this oscillation circuit according to a set frequency division ratio. a frequency dividing circuit that cycles, a counting circuit that counts the number of pulses from this frequency dividing circuit and inverts the signal from the output terminal from, for example, an "L" level to an "H" level when the counted value reaches a predetermined set number; It is constituted by an IC element organically connected to a reset circuit that resets this counting circuit and stops the operation of the oscillation circuit.

A transistor 2 of the switching circuit is connected to the output terminal of this timer circuit via a resistor 25.
The base of the transistor 26 is connected to the base of the transistor 26, the collector of the transistor 26 is connected to the (+) side of the smoothing capacitor 14 through the coil of the second relay 27, and the emitter is connected to the (-) side of the smoothing capacitor 14. There is.

Next, the operation of this embodiment will be explained.

When power is applied to the primary side of the transformer 12, the transistor 20 is turned on, so that the first relay 15 is operated almost simultaneously, and the timer circuit 24 is also operated, and after the set time elapses, the timer circuit 24 outputs a signal from the timer circuit 24. Transistor 2 depending on the output signal
6 is turned on, the second relay 27 is activated. On the other hand, when the power is turned off, the smoothing capacitor 14
Timer circuit 24 and transistor 20 are turned off according to the discharge characteristics of . At this time, if the off level of the transistor 20 is adjusted by the variable resistor 19 and set to a potential higher than at least the return level of the timer circuit 24, the first relay 15 will return earlier than the second relay 27. Become.

When this timer device is applied to a circuit in which the relay contacts of the first relay 15, the second relay 27, and the timer device are connected in series, and the timer device is self-maintained by the relay contact of the first relay 15. This is effective because it eliminates the problem of the structure shown in FIG. 3, where self-holding is not released when the relay contact of the second relay 27 is opened.

Further, even if the level adjustment circuit 16 is inserted in series with the coil of the first relay 15, there is no problem that a low voltage is applied to the coil of the first relay 15 during operation. In other words, it is only necessary to set the power supply voltage appropriately, and the rated value of the power supply voltage is set by the input voltage when the timer circuit operates, and the rated value of the power supply voltage can be set without causing any trouble to the operation of each part. It is possible.

In the above embodiment, since an AC power supply is used, the power supply circuit 11 is replaced by a transformer 12 and a rectifier 1.
3, but they can be omitted if a DC power source is used.

〔Effect of the invention〕

According to the present invention, a smoothing circuit is connected to the power supply circuit, and a first relay, a timer circuit, and a second relay controlled via a switching circuit operated by the output from the timer circuit are connected to the smoothing circuit. A level adjustment circuit that changes the return level of the first relay is inserted in series with the first relay, so if the power supply circuit is turned off, the level adjustment circuit will adjust the level adjustment circuit. Therefore, the first relay can be reliably restored earlier than the second relay, and depending on the application, it can be applied to sequence control where one relay needs to be restored earlier than the other relay.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a conventional timer device, Fig. 2 is an explanatory diagram of its operation, Fig. 3 is a self-holding circuit diagram using the above-mentioned conventional timer device, Fig. 4 is an explanatory diagram of its operation, and Fig. 5 FIG. 1 is a circuit diagram showing an embodiment of the present invention. 11...Power supply circuit, 14...Smoothing capacitor,
15...first relay, 16...level adjustment circuit, 24...timer circuit, 26...transistor of switching circuit, 27...first relay.

Claims (1)

[Claims] 1. A power supply circuit, a smoothing circuit connected to this power supply circuit, a first relay connected in parallel to this smoothing circuit, and a first relay connected in parallel to the smoothing circuit and operated by the output from the smoothing circuit. and a timer circuit that inverts the output signal after a set time elapses;
A switching circuit that performs a switching operation based on an output signal from the timer circuit, and a second relay that is connected in parallel to the smoothing circuit and is controlled by the switching operation of the switching circuit, and the first relay A timer device characterized in that a level adjustment circuit is inserted in series for changing the return level of the first relay.