SU530367A1 - Time relay - Google Patents

Description

(54) TIME RELAY

3

3J. The schematic diagram of the proposed time relay.

The time relay contains an RC circuit consisting of f e3HCTOpa 1 and capacitor 2. To the output of the RC circuit, the input of the zero-organ of the unijunction transistor 3 is connected to the junction of resistor 1 and capacitor 2. The output stage is filled with transistor 4 with the executive relay 5 as a load, a generator on a single junction transistor 6 with an RC circuit consisting of a resistor 7 and a capacitor 8. This generator serves to periodically excite a zero-body on a single junction transistor 3.

The polarity converter 9 of the power supply voltage is produced in the form of a key on transistors 10 and 11 of different conductivity types, capacitors 12, 13, diodes 14, 15 and resistor 16. Transmitters emitters 10 and 11 through a series-connected capacitor 12 and diode 14 in a straight line The conductivities for the charge current of the capacitor 12 are connected to the negative bus 17 of the power supply. The connection point of the capacitor 12 and diode 14 through diode 15, connected in opposite to diode 14, is connected to bus 17. The bases of transistors 1O and 11 are connected via a resistor 16 to the collector of transistor 10 and to the positive busbar 18 of the power supply and directly to the collector of transistor 19, the base of which connected to the negative rail 17 of the power supply. The collector of the transistor 11 and the emitter of the transistor 19 are connected to each other and to the capacitor 8 of the generator, and through diode 20 to the minus line 17 of the power source.

The plus bus of the converter 9 is connected to the minus bus 17 of the power supply, its minus bus through the transition emitter - base of the single junction transistor 21 - with the time code of the RC circuit (with the connection point of resistor 1 and capacitor 2).

The time relay works as follows.

When voltage is applied to buses 17 and 18, the power starts to charge (I set it to capacitor 2. At the same time, the generator on the single junction transistor 6 and the RC circuit from resistor 7 and capacitor 8 turn on. This generator is used to force zero-zero excitation Al transistor 3. The generator operates at a frequency of 5O-100 Hz and provides a periodic reduction of the switching threshold of the unijunction transistor 3 by 0.5-1.0 in pa due to the voltage drop across the resistor

22, included in his ba ba: l, 1. The voltage across the capacitor 2 approaches the threshold voltage of the unijunction transistor 3, the transistor 3 turns on, and the resistance of its transition emitter — the first base decreases avalanche-like.

As a result, the capacitor 2 is discharged through the unijunction transistor 3 and the resistor 23, on which a positive voltage drop is generated, causing the thyristor 4 to turn on. When the thyristor 4 is turned on, an executive relay 5 is triggered, the contacts 24 of which are connected to the external circuit and fix the end of of time. At the same time, turning on the thyristor 4, the cathode of the Zener diode 25 is connected via diode 26 to the negative bus 17. Since the voltage drop on the lower arm of the voltage separator from the resistors 27 and 28 is the same as the voltage on the diode 26 and the thyristor 4, capacitor 2 is able to discharge to zero, which ensures the stability of the time delay when the relay is turned on again.

Claims (2)

1. The time relay containing the time setting between the poles of the power source and the driving RC circuit, the output of which is connected to the input of a null organ on a single junction transistor, an output stage with an executive relay as a load, a generator on a single junction transistor with an RC circuit serving periodic zero-organ excitation, characterized in that, in order to increase the thermal stability of time exposures, it contains an additional unijunction transistor and a polarity converter of the power supply voltage, while and said bus converter is connected to the negative power supply bus, the negative bus through the transducer emitter-base junction of additional unijunction transistor soedineia svyhodrm time specifying RC-circuit. 2. The relay according to claim 1, stating that the polarity converter of the voltage of the power source is made in the form of a key on transients of different conductivity types, connected by emitters through a series-connected capacitor and a direct conduction diode for the charge current of the capacitor to the minus bus from the power supply source; in parallel, the diode is connected to a circuit from another diode connected back to the first, the bases of the said transistors are connected to the collector of the transistor through a resistor -conductance of the key and the plus bus of the power source and directly with the collector of the input transistor of the converter, the base of which is connected to the negative bus of the power source, and its emitter and collector of the transistor p - t) - p-conductivity of the switch dinene between themselves and with the capacitor of the PC circuit of the generator and through a diode with a negative power supply bus.