SU871307A2 - Flip-flop device - Google Patents

Description

(54) TRIGGER DEVICE

The invention relates to the field of pulsed technology and automation and, in particular, can be used in control circuits and counters. The known scheme of the trigger device for the main auth.St. 785960, performed on two transistors with a base bias and a rectifier according to the voltage doubling circuit 1 This circuit solution allows the trigger device to operate in the mode of self-oscillations on only one fixed frequency, i.e. The known device has limited functional capabilities. The aim of the invention is to extend the functionality and ensure operation in self-oscillation mode at two fixed frequencies. The goal is achieved by the fact that in a trigger device containing two transistors, the collectors of which are connected to the corresponding output buses and through load resistors to the power bus, emitters to the Common bus, the base of the first transistor is connected to the first output of the bias resistor and through parallel The first accelerating capacitor and the first coupling resistor are connected to the collector of the second transistor, the base of which is connected to the first output of the second bias resistor and through a parallel connected second accelerating switch. a capacitor and a second communication resistor — with the collector of the first transistor; a voltage doubled rectifier connected between one of the output buses and the second terminals of the bias resistors; a threshold device, such as a Schmitt trigger, whose input is connected to the output of the rectifier / output through a current-limiting input the resistor is to the second pins of the bias resistors. The drawing shows an electrical schematic diagram of a trigger device. In the device, the collectors of transistors 1.2 are connected, respectively, to the output buses 3.4 and through the corresponding load resistors 5.6 to the power supply bus 7, the emitters of transistors 1.2 are connected to the common bus 8, between the base of transistor 1 and the collector of transistor 2 are turned on parallel the first accelerating capacitor 9 and the first resistor 10 of the connection, and between the base of the transistor 2 and the collector of the transistor 1 are connected in parallel the second accelerating capacitor 11 and the second resistor 12 of the connection, the first biases of the resistors 13, 14 are biased respectively, to the bases transistors 1,2, and the second leads to the output of the rectifier 15 with a doubling of the voltage across two diodes 1B, 17, are connected in series in the forward direction between the output of the rectifier 15 and the common bus 8, and two capacitors 18.19, a capacitor 18 is connected between the rectifier input 15 connected to the output bus 4 and the diode anode 17, and the capacitor 19 is connected between the output of the rectifier 15 and the common bus 8, the output 20 of the threshold device 21 (Schmitt trigger) is connected to the output of the rectifier 15 22 which through the current-limiting resistor 23 is connected with the second terminals of the bias resistors 13,14 (and hence with the input 20 of the threshold device 21).

The device works as follows.

When switching a trigger device with a sufficiently low frequency, the potential at the output of the rectifier 15 remains approximately zero. Increasing the switching frequency of the trigger device at the output of the rectifier 15, a negative potential appears due to the conversion of the collector voltage of transistor 2 by the rectifier 15, which through resistors 13, 14 goes to the bases of transistors 1.2 and leads to self-oscillations. But this potential does not exceed the threshold of the threshold device 21 (the Schmitt trigger does not overturn. If you stop the forced switching of the trigger device, auto-oscillations are set at the first fixed frequency.

With a further increase in the switching frequency of the trigger device, the negative potential at the output of the rectifier 15 increases and as the threshold increases, the threshold device 21 results in a negative potential at its output 22, which through the current limiting resistor 23 is fed to the second ends of the resistors 13, 14 to the input of the 20th threshold device. When the trigger device is forced to be switched off, auto-oscillations are established.

at the second fixed frequency (with Schmitt trigger overturned).

Auto-oscillations can also occur at the first fixed frequency when a negative pulse is applied5. polarity not exceeding the amplitude of the threshold of triggering the threshold device 21 at the output of the rectifier 15, and at the second fixed frequency, when a negative polarity pulse is applied that exceeds this threshold.

The introduction of the proposed trigger device will lower the cost of the equipment, expand its capabilities, simplify the RDD circuits, increase their reliability.

nosti, will facilitate their setup.

Claims (1)

Invention Formula The trigger device for auth. 785960, characterized in that, in order to expand the functionality and ensure its operation in self-oscillation mode at two fixed frequencies, a prog device is inserted in it, for example a Schmitt trigger, whose input is connected to the output of the rectifier, and the output through the current-limiting the resistor is to the second pins of the bias resistors. Sources of information taken into account in the examination 1. USSR author's certificate No. 785960, cl. H 03 K 3/286, 10.07.78.