SU567184A1 - Timer relay - Google Patents

Description

(54) TIME RELAY

total voltage across the diode 12, the emitter junction of the transistor 9, the diode 13, the resistor 14, the additional time of the master C circuit on the resistor 15 and the capacitor 16, the additional threshold cascade on the Zener diode 17, the additional key transistor 18, which grants permission to turn on an executive relay 19, an output key transistor 20, a resistor 21 that communicates with a common connection point of the keys of transistors 18, 20 and the base of a cell transistor, contacts 22 and 23 of the sensor for monitoring air flow in the pipeline entil tori local ventilation (PTS), the first of which serves to trigger the relay time during normal ventilation of blind generating second prepares incorporation actuating relay circuit 19 and, if abnormality Ventilation mode disables the output relay 19.

In the initial state, transistors 9, 24 are open until saturation, and transistor 8 is locked. Transistor 9 is open across the circuit: "plus power source - resistor 25 - diode 26 - emitter junction of transistor 9 - collector-emitter of an open transistor 24 - emitter junction of a key transistor 20 - minus power source.

Transistor 24 is open across the circuit: "plus power supply - resistor 27 - zener diode 28 - emitter transitions of transistors 24 and 20 -" minus power supply.

Since transistor 24 is open, the voltage across resistor 14 is equal to the bullet. Therefore, the transistor 29 is locked, and therefore the transistor 3 of the self-oscillating multivibrator of the clock generator 1 is also locked, with the result that the transistors 2 and 5 are open until saturation. Reed switch 4 is turned on, and its contacts 10, And closed. The timing of the drive capacitor 6 is charged to a voltage approximately equal to the voltage of the power source. Condenser 30 discharge.

The time delay starts counting at the moment of obtaining permission from the air flow monitoring sensor in a dead-end mine (during normal ventilation, after the VMP is operational, the air flow sensor contacts 22 and 23 are closed).

With the charge current of the capacitor 30, transistor 8 is unlocked. Since the voltage across the collector of transistor 8 becomes less than the breakdown voltage of Zener diode 28, the latter closes, which leads to the locking of transistor 24 and the appearance on the emitter of transistor 9 of a positive potential defined by a divider on resistor 31 and diode 13, resistor 14.

Since the voltage on the resistor 14 becomes greater than the voltage on the collector of the open transistor 8 and on the diode 32, the diode 26 is closed. At the same time, the diode 12 is also locked, since the block voltage of the capacitor G is applied to it. Therefore, the transistor 9 is also locked.

When the transistor 9 is locked, the voltage across its collector increases. In this connection, the transistor 8 is removed in the open state and after the charge of the capacitor 30. The time setting capacitor 6 begins to charge along the circuit: "plus the power supply - resistor 7 - magnetically controlled

pin 10 - capacitor G - pin 22 - collector-emitter of transistor 8 - resistor 33 - "minus power supply.

Simultaneously with the closing of the transistor 24, the transistor 29 opens and closes the circuit

the emitter of the transistor 3. The self-oscillating multivibrator begins to generate pulses with a certain duty cycle, and the magnetically controlled contacts 10, And periodically (with the frequency of the self-oscillating multivibrator) turn on and off. Thus, the recharge of the driving capacitor 6 occurs in pulses during the time intervals when the magnetically controlled contacts 10 and 11 are closed.

The separation of the time of its resistor 7 from the bias circuit (resistor 25, diode 26) of transistor 9 is used to increase the resistor time of the set resistor 7 to Mom units (in this embodiment, the time relay is about 3 MΩ).

In order to reduce the leakage time of the driver capacitor 6 on the time delay, the optimum value of the threshold voltage of the transistor 9 is chosen. For

This emitter of transistor 9 is connected to a divider: resistor 31 and diode 13, resistor 14. To eliminate the effect of the voltage divider on the initial voltage on the capacitor 6, the resistor 14 and diode 13 in the initial state are shunted by the key transistor 24 controlled by the transistor 8 .

The termination of the generation of pulses by the clock generator 1 occurs at the time of the reverse tilting of the wake-up, its multivibrator on the transistors 8 and 9, when the transistor 29 is closed.

The work of the Executive relay 19 time relay is as follows. In the normal mode of airing a dead-end

After the operational start-up of the V.NP, the contacts 22 and 23 of the sensor for monitoring the air flow rate in the VMP pipeline are closed, which leads to the start of the time relay (pin 22) and the supply of the supply voltage

to the output key transistor 20 with the executive relay 19.

The executive relay 19 does not turn on, because simultaneously with the switching on of the contacts 22 of the air flow sensor, the transistor 8 opens, the diode 34 is opened, the zener diode 28 and the output key transistor 20 are locked.

If in the initial stage of testing a given time delay (in the first seconds

mining) dangerous failures of elements of the relay

time is absent (stopping in the onioivi state of the reed switch 4 of the clock generator 1, failure (short circuit of the electrodes) of the transistors 8, 9, 24 of the standby multivibrator or of the output key transistor 20), then the C-value recharge time will have time to charge to the level of the normal voltage of the zener diode 1 /, which breaks through and holds in the open state the dimmable key transistor 18.

The executive relay 19 remains in the off state until a reverse tilting occurs, the multivibrator on transistors 8 and 9 and the key transistor 20 opens. At the time of the multivibrator tilting, the executive relay 19 turns on and remains in this state until it turns off contacts 23 of the sensor controlling the air flow in the ductless pipe system in violation of the normal mode of ventilation. Simultaneously with the activation of the executive relay 19, the additional key transistor 18 becomes self-locking via the contact 35 of the executive relay 19 and the resistor 36, not interfering with the normal operation of the time relay.

If there are failures of elements of the time relay leading to dangerous consequences, the executive relay 19 will not be turned on, thus preventing an accident.

So, when the clock generator 1 is out of order, at which the reed relay 4 remains in the on state, the waiting multivibrator on transistors 8 and 9 will work out the minimum time delay, which is determined by the parameters of its master C-circuit time. in the time of charge (discharge) of the capacitor b and the threshold value at which the multivibrator reverse tilting occurs (in our case it is 4U s).

In this case, transistors 9, 24 and the output key transistor M will open, however, the switching relay 19 will not turn on, since the additional key transistor 18 will be closed at this time. The transistor 18 is closed because during the processing of the minimum time delay (40 s) the capacitor 16 additional time of the master / C-circuit does not have time to reach the voltage level of the zener diode 17 (it reaches it in the time which in our case is equal to 60 s) the zener diode is closed, which means the transistor 18 is also closed. After the multivibrator is tipped back over (after working off the minimum time delay), the capacitor 16 cannot continue charging because it is shunted by the open transistor 24.

Similarly, danger is excluded. 1 st premature switching on of actuating relay 19 upon shutdown at the initial moment of working off the time delay of transistors 8, 9, 24.

When the output key transistor 20 fails (the short circuit of its electrodes leads to the dangerous switching on of the executive relay 19), due to the connection of its collector through a resistor to the base circuit of the key transistor 5 of the clock generator 1, the reed switch 4 is fixed in the on state, which leads to testing with a waiting multivibrator on transistors 8 and 9 for the minimum time delay, after which transistors 9, 24 and 20 are opened, and executive relay 19 does not turn on due to the locked state of the additional transistor 18 for a reason similar to the above.

Due to the connection of these additional elements, it is possible to exclude the most dangerous inclusions of the executive relay 19 due to the failure of the time relay elements at the initial moment of time delay.

Claims (1)

1. USSR author's certificate 9 468568, cl. And 01H 47/18, 1973.