SU660253A1 - Dc switch - Google Patents

Description

one

The invention relates to a pulse technique and can be used in control systems for the communication of logic elements made on electromagnetic relays (for example, on reed switches) with active-inductive loads.

A DC switch is known, which contains an electromagnetic relay, a thyristor connected in series with the load between the poles of the power source, resistors and a capacitor providing unlocking and locking of the thyristor depending on the state of the contacts of the relay 1.

The disadvantage of such a key is the criticality of its work | to overvoltages in the supply network and on active-inductive load.

. The closest technical solution to the invention is a dc switch containing an electromagnetic relay, a thyristor connected in series with the load. between the poles of the power supply, a series of resistors and a diode connected in the opposite direction parallel to the load, a capacitor connected in parallel to the thyristor through a breaker, a relay contact, and a resistive voltage divider 2.

The disadvantage of this key is its relative complexity.

The purpose of the invention is to simplify the device.

Claims (2)

The goal is achieved by the fact that, in the current strength switch, which contains an electromagnetic relay, a thyristor connected in series with the load between the poles of the power source, a series circuit from the first resistor and a diode connected in the opposite direction parallel to the load, the second resistor and a capacitor, the first plate which is connected to the point of connection of the load and the output electrode of the thyristor, the other output electrode of which is connected to the second capacitor plate through the disconnecting contact of the relay, is introduced a light emitting diode, a thyristor is made light-guided, and a light emitting diode is connected by one electrode to the second capacitor plate through the closing contact of the relay, and the other electrode is connected to the midpoint of the series circuit from the first resistor and diode through the second diode. 3 The drawing shows a circuit diagram of a key. The DC switch contains an electromagnetic relay 1, an optocoupler 2, whose thyristor 3 is connected in series with the load 4 between the poles of the power source, a series circuit of the first resistor 5 and diode 6 connected in the reverse direction parallel to the load 4, a capacitor 7 and the second resistor 8. The first capacitor plate 7 is connected to the cathode of the thyristor 3, and the second plate is connected to the thyristor anode via the disconnecting contact 9 of the relay 1 The light-emitting diode 10 of the optocoupler 2 is connected by an anode to the second plate of the capacitor 7 contact 11 of relay 1, and the cathode to the midpoint of the chain of resistor 5 and diode b through resistor 8. The device works as follows. Let the power supply be turned on and the control voltage is missing. Then the thyristor 3 is closed, and the capacitor 7 is charged through pin 9 and load 4 before the voltage of the power source. When a control voltage is applied to the winding of the relay 1, the last is triggered, contact 9 is opened and contact 11 is closed. As a result, the charged capacitor 7 starts to discharge through light-emitting diode 10, resistor 8 and diode 6 and turns on the thyristor 3. Power supply is applied to the load 4a, the capacitor 7, through pin 11, the light emitting diode 10, and the resistors 8, 5, is recharged to the load voltage 4. When the control voltage is removed, contact 9 returns to its initial closed state by connecting the recharged condenser 7k to thyristor 3. As a result, a reverse voltage is applied to thyristor 3 and it closes, thus interrupting the current in the load. The transients in active-inductive load are damped by means of diode 6 and ezistor 5. Thus, diode b performs all functions: it suppresses overvoltages on load 4 and closes the thyristor turn-on impulse formation circuit, and the capacitor 7 - three functions: provides turning on the thyristor, its shutdown and protection against overvoltages. This makes it possible to reduce the number of JMeHTOB B devices and, accordingly, simplify its design. The invention of a key current comprising an electromagnetic relay, a thyristor connected in series with the load between the poles of the power source, a series circuit from the first resistor and a diode connected in the opposite direction parallel to the load, the second resistor and a capacitor whose first face is connected to the load connection point and the output electrode of the thyristor, another output electrode of which is connected to the second capacitor plate through a disconnecting contact of the relay, characterized in that, Strongly simplify device introduced into it light-emitting diode, and a thyristor formed svetoupravl emym, wherein the light emitting diode is connected with one electrode of the second electrode of the capacitor via a make contact of the relay, and the other electrode - a midpoint serial chain of a first resistor and the diode through the second resistor. Sources of information taken into account in the examination 1. I. Dziubin I. And, Thyristors in pulse circuits. Energy, 1972, fig. 31a. 2. Japan patent No. 50-23138, cl. 98 (5), 1975. P. L. P five KZ