SU1352547A1 - Switching device - Google Patents

Abstract

The invention relates to low-voltage electrical apparatus and can be used in protective devices of automation. The purpose of the invention. - Increased operational capabilities. The discharge diode 5, introduced into the switching device, is connected by an anode to a common point of resistor 3 and a damping capacitor 4, and the cathode is connected via a charging resistor 6 to output 10 to connect an AC power source. Such a connection allows the capacitor 4 of the damping circuit to be discharged without exceeding the voltage threshold of the contactless switch 2 of the switching device increasing on it. When the supply voltage decreases or disappears, the response threshold is exceeded, the contactless switch 2 is opened and the additional capacitor 7 is discharged to the load. Because the additional capacitor 7 is connected in series with the load B and 9, the device allows to apply a current pulse to the load when the supply voltage is applied and when it is removed, which increases its operational capabilities. with (L il. 4 Cp. f-ly. 52i Z ate el SP o 4 (Puz.1

Description

The invention relates to low-voltage electrical apparatus, in particular, to automatic protection devices.

The purpose of the invention is to increase the operational capabilities.

FIG. 1 is a circuit diagram of a switching device; FIG. 2-D - the same options.

The device contains a one-half-one rectifier 1, a contactless switch 2, which is a thyristor. A damping circuit consisting of a series-connected resistor 3 and a capacitor 4, connected in parallel to the contactless switch 2, and a resistor 3 connected to the connection point. half-wave rectifier 1 and non-contact key. 2, the capacitor 4 is connected to the cathode of the contactless switch 2, and the control electrode of the latter is connected between the resistor 3 and the capacitor 4. The anode of the discharge diode 5 is connected here. The discharge resistance 6 is connected in series with the discharge diode 5, the value of which the minimum amplitude of the voltage from the network at which the switching device operates. Another output of the discharge resistance 6 is connected to the anode of the half-wave rectifier 1. An additional capacitor 7 is connected in series with the loads 8 and 9 (which are switching electromagnets) between the latter connection point and the connection point of the half-wave rectifier 1 and contactless switch 2. To terminals, 10 and 11, a variable network pitch is applied. For the operation of the device must comply with the inequality

-6 1

2fln (1-U, / i)

De ZT is the time constant of the damping circuit, defined as the product of capacitor capacitance and resistance;

f is the mains voltage frequency, 55 const;

Ug is the threshold voltage for unlocking the contactless key, const;

Ug is the voltage amplitude of the network const.

The device works as follows.

In the absence of voltage at terminals 10 and 11, the capacitors 4 and 7 are discharged and prepared for operation. When the supply voltage is applied during the passage of the positive half-wave, the one-half-period rectifier 1 is unlocked and the additional capacitor 7 is charged, resulting in 8 current impulse flows. The duration of the current flowing through the load is determined by the product of the capacitance value of the additional capacitor 7 and the load resistance 8. Simultaneously with this process, the capacitor 4 of the damping circuit through the resistor Z is charged. At that, the voltage across the capacitor of the net voltage should not have time to reach a level equal to the threshold voltage of unlocking the semiconductor key 2. When the polarity of the network voltage is changed to negative, the one-half-full will emit Spruce 1 is closed and discharge diode 5 is unlocked and capacitor 4 is discharged through discharge resistor 6, while returning to its original position. When the polarity of the mains voltage changes to a positive half-wave rectifier 1, it opens again, an additional capacitor is charged and so on until it is fully charged. Subsequently, only the charge of the damping circuit of the capacitor 4 occurs. In this case, the currents flowing through the damping circuit are determined by the resistance values

3 - capacitor 4 may be negligible compared to load currents.

When you turn on the mains voltage or reduce it to a certain amplitude, the voltage on the capacitor

4 reaches the threshold voltage level by unlocking the contactless key 2. This is due to the absence of a discharge of the capacitor 4 or its incomplete discharge. As a result of unlocking the contactless switch-2, the additional capacitor 7 is discharged, and a current pulse flows through the load 9. Since loads B and 9 are electrically

switching magnets, then at the moments of switching on and off, the proposed device is capable of performing specified switching.

The device can be made in various modifications depending on the functional conditions. For example, if impulse switching of any devices is required when the mains voltage is turned on, a current limiting resistance is turned on (Fig. 2). If switching is required when the mains voltage is turned off, the load is switched on, as shown in FIG. 3. In FIG. Figure 4 shows a modification of the design of the device; the device if it is necessary to carry out impulse switching both at the time of turning on the network voltage and at the moment of turning it off.

Claims (5)

1. A switching device containing a contactless switch, terminals for connecting an AC source, a current, terminals for connecting a load, a damping circuit including a series-connected resistor and a capacitor, a rectifier, a discharge resistor, an additional capacitor, and a damping circuit connected in parallel to the non-contact The key and the rectifier are connected to the first terminal for connecting the AC source, characterized in that, in order to increase the operational capabilities, in The discharge diode is used and three pins are used to connect the load, the diode is connected by an anode to a common point of a resistor and a damping capacitor, and the cathode is connected via a discharge resistor to the first terminal to connect a power source, the first plate of the additional capacitor is connected to the first output terminal load, the second plate of the additional capacitor is connected to the first output of the contactless switch, the second output is un 2547; The jBKTHoro key is connected to the second output pin for connecting the load, the second pin for connecting the power source is combined with the third pin for connecting the load, the damping circuit is made with a constant time greater than a predetermined constant value defined by 10 ratio C 2 fln (1-Uo- / Uq) where -, o is the time constant of the damping circuit, defined as the product of capacitor capacitance and resistance; mains voltage frequency, const; threshold voltage for unlocking the contactless cable and „5 0 five 0 five 0 cha, const; UQ network voltage amplitude, const. 2. The device according to claim 1, characterized in that the load is made of two parts, one of which is connected between the first and second terminals for connecting the load, and the other between the first and third pins for connecting the load. 3. The device according to claim 1, characterized in that the load is connected between the first and third terminals connected to the load, and between the first and second high-voltage drives, a limiting resistor is also included to connect the load. 4. The device according to claim 1, wherein the load is connected between the first and second terminals for connecting the load, and between the third and first terminals for connecting the load, an additional limiting resistor is included. 5. The device according to claim 1, characterized in that the first and the third pins for connecting the load, are combined. Fu