SU650223A1 - Delay device - Google Patents

Description

on transistor 5, generator of two-pole pulse signals on transistors 6 and 7, diodes 8 and 9, emitter transistor on transistor 10, triac 11, stabilizer 12 voltage: Yen, voltage divider on resistors 13 and 14, resistors 15-22 , capacitors 23, 24, load 25 and controlled voltage source 26.

The device works as follows.

In the initial state, transistors 3, 5 and 6 are open, and transistors 4 and 7, the bases of which are connected respectively via resistors 15 and 20 to the collector of transistor 5, are closed. As a result, a blocking positive voltage is applied to the cathode of the diode 8 connected to the collector of the transistor 7. The capacitor 2 is charged by the master circuit time: a power source, a normally open key transistor 3, a capacitor 2 and a circuit consisting of a parallel-connected diode 9 and the base-emitter junctions of transistor 5 and the collector-emitter of transistor 6.

When a positive polarity is fed to the input of the triggering device, transistor 4 opens, and transistor 5 closes the negative potential on the capacitor plate 2 connected to its base. The capacitor 2 then begins to recharge with time, the driving resistor 1, the resistor 14 of the voltage divider, the power source and the open transistor 4. The high potential of the NC. the collector of transistor 5, which is fed to the resistor 20, converts the generator of two-polarized pulse signals to the self-oscillatory mode.

When transistor 7 is open, the cathode of diode 8 has zero potential, with the result that the diode is displaced in the forward direction and the base of transistor 4 is shunted by low resistances of the open diode 8 and transistor 7, which causes the capacitor 2 to close. The zero potential of the collector of the transistor 7 closes the same transistor 3, as a result of a winding capacitor 2 does not occur. At the moment of locking the transistor 4, the diode 9 is opened by the current flowing from the power source and shunts the base of the transistor 5, maintaining it in a closed state together with a high polarizing potential at the collector of the transistor 6 connected to the emitter of the transistor 5.

The simultaneous opening of the diode 9 and the locking of the transistor 6 makes it possible to compensate for the effect of the transient process on the discharge of the capacitor 2 during the switching of the generator of two-pole pulse signals.

At the time of the next tipping of the oscillator circuit of two-pole pulse signals operating in self-oscillating mode, the transistor 7 is closed, and

transistor 6 opens. A high positive potential appears on the collector of transistor 7, unlocking transistor 3 and blocking diode 8, as a result of which transistor 4 opens. In this case capacitor 2 is connected in parallel to diode 9, which, in turn, is connected in parallel to the circuit of sequentially connected base transitions emitter of transistor 5

and the collector is the emitter of transistor 6. Therefore, the diode 9 and the transistor 5 are kept in a closed state by a negative potential on the capacitor plate. The capacitor 2 is recharged while the transistor 7 is closed. The high positive potential at the collector of transistor 5 ensures that the transistor 4 is completely open. A circuit consisting of series-connected resistor 16 and an open transistor 3 serves as the collector resistance of transistor 4. When tipping the generator circuit the recharge of capacitor 2 stops until the next positive pulse appears on the collector of transistor 7. This repeats periodically until e on the plates of a capacitor 2 connected to the base of transistor 5 will not reach the voltage to unlock this

transistor. The low potential of the collector potential of the transistor 5 supplied to the resistor 20 closes the transistor 7 and disrupts the self-oscillatory process of the generator of two-pole pulse signals. So

thus, a delay pulse is generated at the device output. The delay device circuit is reset. The diode 9, included in the forward conduction for the charging current, is the time of the driving capacitor 2, and serves in addition to reducing the recovery time of the delay device. The emitter follower on the transistor 10 is a matching element between the transistor 5 and the triac 11.

The resistor 22 limits the magnitude of the control current of the triac, the use of the triac as a controllable element, switching the source of both constant and alternating current, expands

way, the functionality of the delay device. Instead of transistor 5, a MOS transistor can be switched on, allowing the delay pulse to be extended due to a much larger input resistance, the pin of the time of the setting resistor 1 not connected to the gate of the MOS transistor connected to the power supply resistive voltage divider

tension unlock. To reduce the recovery time from the device, a diode 9 in direct polarity can be connected between the gate and the ground bus in direct polarity for charging current, the time of the driving capacitor 2.