SU691942A1 - Capacitor time relay - Google Patents

Description

(54) TIMING CAPACITOR RELAY

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- The invention relates to electrical engineering and is intended to produce adjustable time1 {delay delays between input and output signals. .

The invention can be used in devices for signaling, monitoring, automatic control, and so on. Information about the time relay (I, containing the time of the master circuit (inertial element), time delay fixation device, relay operation control device, output device, power supply

The disadvantage of this time relay is that the stability of the time delay of the signals delays the stability of the master circuit time and the accuracy of fixing the time delay with the corresponding device, while obtaining long exposures of tens and hundreds of seconds requires the presence of a high impedance time delay device .

Most closely related to the technical nature of this invention is a capacitor time relay with an ad-junction transistor containing a control; circuit breaker

valuable in series resistor and capacitor, which is connected in parallel with the device fixing the time delay on the unijunction transistor. In the circuit, the base of the transistor includes low-impedance resistors, the command pulse is removed from the base resistor and is used to switch the thyristor, which is the output device of the time relay.

The command impulse is produced when the switching voltage of the unijunction transistor reaches a capacitor of 50 to 70% of the voltage of the power source. :

A significant disadvantage of this device is its high stability.

and the delay time of the input signal, especially between the initial delay and the subsequent ones, caused by the presence on the capacitor of a residual voltage B, equal to the residual voltage of the transistor junction emitter-base. The high stability is also caused by the use of variable resistors during the drive chains, the resistance of which depends on the temperature.

Another significant disadvantage of the device is that the time lag associated with the incomplete use of the power supply voltage has been neglected.

The aim of the invention is to increase the time lag.

This goal is achieved by the fact that a capacitor time relay containing an adjustable power source, made, for example, in the form of a potentiometer and a storage capacitor, is a single transistor, the time setting of the RC circuit. An electromagnetic-magnetic relay, supplied with a chain, consisting of a zener diode and a resistor connected to the output terminals of the power source, and a junction point of the resistor and the zener diode to the second base of the single junction transistor, the RC chain through the emitter junction - the first base of the transistor and the winding of the output electromagnetic relay is connected to the outputs of the regulated power supply. The relay operates in the discharge mode, the time of the driving capacitor with the stabilization of the charging and discharging voltage.

The discharge voltage is fixed at 0.5–7 V by applying a low-voltage zener diode, while using a power source can reach 97.5%, and the time delay increases by 3–3 times, 5 times when using the same

lead time

0.5g t 3.5g

. Regulation of the input signal delay time, carried out by changing the supply voltage, which allows the use of highly stable elements during the driving circuit, increases the temperature stability of the relay.

A schematic of the invention is shown in FIG. I, and in FIG. Figure 2 shows the discharge time curve of the timing circuit. .

The circuit contains an adjustable power source 1, made in the form of a potentiometer 2 and a storage capacitor 3.

A command contact 4 is connected to the potentiometer's motor, which in turn is connected via a winding of an output electromagnetic relay 5 connecting external circuits to a second base of a single junction transistor. nutrition 1.

Between the emitter of the transistor and the common wire are connected in parallel the time specifying the capacitor 9 and the resistor Y.

The device works as follows.

In the initial position, the circuit is connected to the power supply, and the capacitor 3 is charged. The work cycle begins with the closure of command command 4.

The voltage from the potentiometer slider 2 through the winding at relay 5 is applied to the second base-emitter junction of the transistor 6 in the forward direction, while the time driving capacitor 9 is charged before the voltage on the storage capacitor 3. After that, the first base-emitter junction closes.

A past pulse sets the relay to its original state. The same impulse can be used to prepare for operation of the outer circuits of the circuit.

The emitter junction resistance .-- the first base exceeds 1-10 ohms; therefore, the discharge time of the capacitor 9 is determined by the value of the resistor 10, the discharge lasts until the voltage across the capacitor 9 coincides and the voltage drops

the zener diode 7. Continuing the discharge leads to the opening of the emitter junction - the first base, after which the capacitor 9 Zf again through the winding of the relay 5, performed the working switching of external circuits.

Current in the circuit (potentiometer slider 2,

relay coil 5, first base, second base,

zener diode 7) is determined mainly by

the resistance of the transition base.-base transistor. .

(j-6r 5 9

Resistance coil relay 5 should

choose from the ratio:

R "-0.,

Since at currents below 0.001 A, the stabilizer; 1 nitron 7 ceases to operate in voltage stabilization mode, the power supply voltage through the ballast resistor 8 is applied to it, and the resistance value of resistor 8 should ensure that the minimum Zener diode operating current 7

p and "

where are the supply voltage

It is the current of the zener diode 7.

When using a KTI17 transistor with a working voltage of about 30 V,

R 30 kOhm

The maximum input signal delay occurs at a voltage across storage capacitor 3 equal to the voltage of the power source.

To reduce the delay time, it is necessary to reduce the voltage U on the capacitor 3 by moving the slider of potentiometer 2, while the minimum voltage is determined by the voltage triggered by the OUT.