SU1111252A2 - Trigger device - Google Patents

Abstract

LAUNCHING DEVICE by author. St. No. 352375 characterized by the fact that, with an extension chain, is functional}; Possibly, by providing an additional threshold for triggering, a setpoint RC circuit is introduced, and an additional transistor connected to a common collector, the emitter of the latter defining the RC circuit through time is connected to the input of the trigger device, the output of which is connected to the base of the additional transistor. g

Description

The invention relates to electronic engineering and can be used in automation and relay protection circuits.

According to the main author. St. No. 352375 known a trigger device containing transistors of different conductivity types interconnected by emitters, a collector of one transistor is connected via a diode to the base of another transistor and through a resistor to an input source connected to a collector in parallel - the bases of the same transistor. However, in a known device there is no additional threshold. triggers, which limits the functionality of the trigger device.

The purpose of the invention is to enhance the functionality by providing an additional trigger threshold.

The goal is achieved by the fact that the triggering device containing transistors of different conductivity types, connected between emitters, collector of one transistor is connected via a diode to the base of another transistor and through a resistor to an input source connected to the same transistor, time is set to K-chain. and an additional transistor connected in a circuit with a common collector, the emitter of which through the time of the RC circuit is connected to the trigger input, the output of which is connected to the base of the additional transistor.

FIG. 1 is a schematic diagram of the trigger; in fig. 2 shows the trigger response characteristic.

The release device contains the input voltage connection terminals 1, the transistor 2 of the conduction type 2, the transistor 3 of the conduction type, resistors 4, 5 and 6, the diode 7, the terminal 8 for connection of the negative bias voltage, terminals 9 power connections, output terminals 10, an additional transistor 11 of a pnp type, time specifies a KS circuit, which contains a resistor 1 and a capacitor 13.

The descender operates as follows.

With a negative bias voltage at terminal 8 equal to the supply voltage at terminal 9, the device operates as follows.

If the input current at terminals 1 is zero and transistor 3 is saturated, the current flowing through it determines only the resistance values of resistors 5 and 6 and does not depend on the parameters of transistors 2 and 3. This current r: passes through the emitter-to-transistor 2 transition If the input current is less than the transition current of the emitter - base of the transistor 2, then it flows through the CRL. basic transistor 2.

 When the input current exceeds the current of the emittance & rn-base transition of the transistor 2, the voltage across the collector of the transistor begins to increase, and with a further increase in the input

-current difference of this current and current

The emitter-base junction of transistor 2 flows through diode 7 into the base of transistor 3, thereby reducing the base current of transistor 2, and consequently, the emitter current of transistors 2 and 3. As a result, the blocking current through diode 7 increases even more, and the emitter current of transistors 2 and 3 decreases, etc., i.e. An avalanche-like process develops in which transistors 2 and 3 are closed and the voltage at the output terminals 10 changes abruptly. In this case, the entire input current flows through diode 7. The potential at the base of transistor 3 becomes positive. When the input current decreases, the positive potential at the base of transistor 3 decreases, and when it reaches the value at which current flows through the emitter, ho is the collector current of transistor 2, the emitter current of transistor 3 increases, etc., an avalanche-like process develops, and the device returns to its original state.

In the absence of current or at current 1 less than the magnitude of the first trigger threshold, the output voltage is zero, because transistors 3 and 2 are saturated with the current of resistors 5 and 6, the voltage on the collector of transistor 3 is close to the horn, and therefore close to zero and voltage The output voltage of the transistor is 11. The current level of the first triggering threshold luft is equal to the sum of the currents of the resistors, 5 and 6. If the current Iftx is greater than the first triggering threshold Itpo is less than the second trigger threshold, 2, pulses are generated at the output of the UBMX device. This is because after closing transistors 2 and 3 a high potential appears on the collector of transistor 3 and emitter. Transistor 11 and a current flows through resistor 12 that discharges capacitor 13. The current through resistor 12 is greater than the input current G, so the capacitor 13 straits charge up to negative polarity. When the voltage on the capacitor 13 reaches a value at which transistors 2 and 3 are regeneratively locked, the output voltage becomes zero and the capacitor starts to charge from the input current 1. When the voltage on the capacitor 13 reaches the value at which transistors 2 and 3 is regeneratively closed, the negative polarity voltage is again formed at the output of Ugy, from which again the capacitor 13 begins to recharge. When the voltage on the capacitor 13 decreases to such an extent that the transistors 2 and 3 are regeneratively unlocked, the output {Voltage again becomes equal to zero and the condenser is 8X.

Usr

USR1

- Iltor and void start to be charged with current Ig of positive polarity, etc. The oscillations continue until the voltage I exceeds the level ItP2 equal to the sum of the current over the recharge current through the resistor 12. After the input current Ig becomes greater than the level of the second pickup threshold, transistors 2 and 3 cannot open through the resistor 12 is less than the current, the capacitor cannot be recharged. At the same time, there is a constant high potential on the collector of Transistor 3 and the emitter of transistor 11, which is approximately equal to the source of the negative bias voltage. Thus, in the proposed device, an additional threshold is generated, in this case, if there is a constant high potential at the output, this means that the input current level is greater than the second trigger threshold; if the potential is zero at the output, this means that the input current level is less than the first trigger threshold; if, on the output, there is a continuous sequence of pulses, this means that the input current level is greater than the value of the first threshold to trigger, but less than the level of the second response threshold.

Claims (1)

DESCENT DEVICE by ed. St. No. 352375, distinguished by the fact that, in order to expand the functionality by providing an additional threshold *, a timing RC circuit and an additional transistor are introduced, connected in c ^ seven with a common collector, the emitter of which is connected through the timing RC circuit with the input of the trigger device, the output of which is connected to the base of the additional transistor. /