JPS61177503A - Equipment controller - Google Patents

Abstract

PURPOSE:To obtain an equipment controller which is hard to malfunction and reducible in size by connecting a resistance which has a small resistance value in parallel to an input circuit at a stop, namely, when no voltage is inputted from an external power source. CONSTITUTION:The impedance circuit ZU constituted by connecting the normally open contact Ryb of an output relay Ry and the resistance with the same resistance value in series with each other in parallel to an input circuit, namely, betweenterminals 22 and 23 is provided. Here, the input circuit IU includes the light emitting diode D1 of a photocoupler P, the anode of this light emitting diode D1 and the anode of a constant voltage diode Zd are connected, and a resistance R2 and a capacitor C are connected in parallel between both the cathodes of both diodes D1 and Zd. The cathode side of the diode D2 is connected to the terminal 22 through a resistance R3.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application This invention is characterized by an equipment control device that controls starting and stopping of required equipment in response to the presence or absence of an external signal input, particularly an input section. The present invention relates to an equipment control device having:

(b) Conventional technology In general, an input circuit such as a photocoupler determines whether an external signal (voltage) is input manually, and the on/off state of the input is determined by a control unit comprising a timer circuit or the like. There is an equipment control device that controls starting and stopping of equipment by transmitting information to the controller and controlling the output from the control unit. A circuit example of this type of equipment control device is shown in FIG. In the figure, the internal circuit section CC is provided with terminals 21, 22, and 23 for external connection. An AC power source E is connected between terminals 21 and 22, and a start/stop switch SW is connected between terminals 21 and 23.

In the internal circuit section CC, the power supply circuit PU is connected between terminals 21 and 22.
is connected to convert the applied AC power supply voltage into a voltage of a required level, for example, rectify it and apply it to the timer circuit TU. On the other hand, an input circuit IU is connected between terminals 22 and 23. When the switch SW is turned on/off, this input circuit IU detects whether voltage from the AC power supply E is applied or not applied in response to this on/off, and sets the presence or absence of this input voltage.・
The information is transmitted to the reset circuit SRU. Further, the set/reset circuit SRU applies a set signal or a reset signal to the timer circuit TU depending on the presence or absence of the transmitted input voltage. The timer circuit TU performs the required timer operation based on the signal from the center/reset circuit SRU, turns on/off the output relay R)I, and controls the start/stop of the load equipment by the on/off operation of the output relay Ry. It is supposed to be done.

(c) Problems to be solved by the invention When the above-mentioned conventional device control device is incorporated into a device to configure a control system, externally connected start/stop switches and power sources are required for remote control. Furthermore, wiring for electromagnetic relays and the like is often extended long from the internal circuit section. In this case, if power lines, etc. are installed in parallel near the wiring, an induced voltage E1 from the power lines, etc. may be induced on the input side of the input circuit, as shown in Figure 4(a). . Furthermore, as the wiring becomes longer, the line-to-line stray capacitance C increases, and as shown in FIG. Therefore, the line-to-line drift capacity C
The larger the value, the closer the short-circuit state between the terminals 21 and 23 becomes, and the larger the residual voltage E2 between the terminals 22 and 23 of the input circuit becomes.

If the induced voltage E or residual voltage E as described above is large,
Even if the start/stop switch SW is not turned on, the input circuit responds to the above-mentioned induced voltage El and residual voltage E2, adds a signal meaning "on" to the set/reset circuit, operates the output relay Ry, and activates the external device. There is a risk that it will start up without permission.

Therefore, in order to solve this problem, there is a method of connecting a low-resistance resistor in parallel to the input side of the input circuit to lower the impedance of the input circuit when no AC power supply voltage is input, that is, when the switch SW is off. Conceivable. However, if a low resistance is connected in parallel to the input circuit, a large current will flow through the low resistance when power is input, that is, when the switch SW is turned on, resulting in large power consumption. Furthermore, since a large current flows, a large resistor with a large wattage must be used, which means that the circuit board on which this resistor is mounted also becomes large, which hinders miniaturization of the device. was there.

In view of the above, it is an object of the present invention to provide a device control device that is less prone to malfunctions and can be downsized.

(d) Means for Solving the Problems The device control device of the present invention has a relay contact (R) that is opened and closed in parallel with the input circuit (TU) in response to control status B (on/off) of the device. lb) and a resistor (R1) for reducing the human input impedance of the input circuit are connected in series to form an impedance circuit (ZU).

(E) Function In this device control device, when the device is in the OFF state, the relay contact is closed and a low resistance is connected in parallel to the input circuit, so the input impedance of the input circuit is small and there is no induced voltage. Does not respond to residual voltage. However, when the start switch is turned on and the MWS is turned on, the relay contacts are opened, so no current flows through the resistor and no power is consumed from then on.

(f) Examples The present invention will now be explained in more detail with reference to Examples.

FIG. 1 is a circuit block diagram of a device control device showing an embodiment of the present invention. This embodiment device has a basic configuration similar to that shown in FIG. 3, but has a low resistance value and a normally closed contact Ryb of an output relay Ry connected in parallel to the input circuit IU, that is, between terminals 22 and 23. An impedance circuit ZU is provided in which resistors R are connected in series.

Here, the internal connections of the input circuit IU will be explained. The input circuit IU includes a light emitting diode D1 of a photocoupler P, the anode of the light emitting diode D is connected to the anode of a constant voltage diode Zd, and a resistor R2 and a capacitor are connected between the two power sources of the diodes D1 and Zd. C
are connected in parallel, the cathode side of the light emitting diode D is connected to the terminal 23, the anode of the diode D2 is connected to the cathode side of the constant voltage diode Zd, and the cathode side of the diode D2 is connected to the terminal 22 via the resistor R1. ing.

In this example device, when the switch SW is in the OFF state, the relay contact Ryb is closed and the impedance circuit ZU is connected in parallel to the input circuit [U, so the input impedance of the input circuit IU is small, and therefore the inductive Even if voltage enters the input side, the input circuit IU does not operate. In other words, the light emitting diode D1 does not light up.

When switch SW is turned on, voltage is input from AC power supply E through switch SW and terminal 22.23, current flows through light emitting diode D of photocoupler P, and switch SW is turned on by photocoupler P to set/reset circuit SRU. A signal is transmitted indicating that the The set/reset circuit SRU adds this signal to the timer circuit TU,
Activate (turn on) relay Ry. This operation of relay Ry activates equipment not shown. In addition, the relay contact Ryb opens due to the operation of the relay Ry, and the resistor R8 is connected to the input circuit I.
Separated from U. Thereafter, no current flows through the resistor R1 while the relay Ry is in operation, that is, while the device is in operation, and no current is consumed in the resistor R1 during this time.

The timer circuit TU has an off-delay function and a start-up memory function, and when the AC power is cut off, the light emitting diode D turns off, and the reset circuit SRU turns off the timer circuit TU.
start the timer.

If the power is cut off, relay Ry is off and relay contact Ry
b is also closed, and therefore the impedance circuit ZU is connected in parallel to the input circuit IU during this time. If the power is restored before the timer completes the time amplification, relay Ry
is turned on again and the device is restarted. When relay Ry is turned on, relay contact Ryb is closed, so
Impedance circuit ZU is disconnected from input circuit IU.

If the power is restored after the timer expires, relay Ry is not turned on and the device is not activated.

If only the resistor R1 is simply connected to the input side of the input circuit U, the power will be consumed by the low resistor R3 while the power is turned on, as shown in Figure 5(a), so the power consumption will be reduced. However, in this example device, as shown in Fig. 5(b), current is passed for a short time t during startup, and no current is passed through resistor R1 while the device is operating, so power consumption is extremely low. becomes smaller.

FIG. 2 is a circuit block diagram of a practical equipment control device in which some circuits are added to the embodiment device of FIG. 1. The configuration of the internal circuit section CC of the device control device of this embodiment is the same as that in FIG. Terminals for external connections 21, 22.
In addition to 23, 24.25 is attached. Further, outside the internal circuit section CC, a start switch SWA and a stop switch SWB are connected in series and connected between terminals 21 and 23. The switch SWA has an automatic return type a contact, and the switch SWB has an automatic return type b contact. Further, an AC power source E is connected between terminals 21 and 22, and an electromagnetic coil MC of an electromagnetic switch for controlling external equipment is connected between terminals 22 and 23. In addition, the auxiliary (self) contact MCa of the electromagnetic switch is the starting switch SWA.
are connected in parallel. Further, the common connection point of switches SWA, SWB and contact MCa is connected to terminal 24, further, terminal 25 is connected to terminal 21, and meter contact Rya of relay Ry is connected between terminals 24 and 25 in internal circuit section CC. ing.

In this equipment control device, when the start switch SWA is turned on, voltage is applied from the AC power source aiXE to the input circuit IU, the light emitting diode D+ of the input circuit IU lights up, and the first
Relay R)1 operates in the same manner as the device shown in the figure, and contact Ry
a closes and maintains the activated state, current flows through the electromagnetic coil MC, and activates the external device. When current flows through the electromagnetic coil MC, the contact MCa closes and is self-held. after that,
When the stop switch SWB is operated, the current flowing through the electromagnetic coil MC is cut off, the operation of the device is stopped, and the contact MCa is also opened. Further, by operating the switch SWB, the contact Rya is also opened, and the state before startup is established. The effect of the impedance circuit ZU is similar to that of the embodiment shown in FIG.

(G) Effects of the Invention According to this invention, when stopped, that is, when voltage is not applied manually from an external power source, a resistor with a low resistance value is connected in parallel to the input circuit, so the input impedance of the input circuit is small and the inductive Even if there is voltage or residual voltage, it will not malfunction, and when voltage is input and the device is started, the low resistance mentioned above is disconnected from the input circuit, so power consumption by the low resistance is reduced while the device is operating. Therefore, this low resistance can be miniaturized, and the mounting space on a printed circuit board or the like can be correspondingly reduced, so that the entire device control device can be miniaturized.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a device control device showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a practical device control device obtained by adding some circuits to the same device, and FIG. 4(a) and 4(b) are diagrams for explaining the problems of the conventional device, and FIGS. 5(a) and 5(b) are circuit diagrams showing a conventional equipment control device.
1 is a diagram for comparing the power consumption of the conventional device and the above embodiment device. IU: input circuit, Ryb: relay contact, R1 two resistances,
ZU: Impedance circuit, patent applicant
Tateishi Electric Co., Ltd. Agent Patent Attorney Medium
Shigeru Mura Magnification 4 Figure 5

Claims (1)

[Claims] (1) In a device control device including an input circuit that, when an on/off signal is input as a control input, transmits this on/off signal to a control unit that controls an external device, in parallel to the input circuit, the A device control device comprising an impedance circuit formed by connecting in series a relay contact that opens and closes depending on the control state of the device and a resistor for reducing the input impedance of the input circuit.