SU718893A1 - Flip-flop - Google Patents

Description

The invention relates to the field of electrical radio engineering and can find application in pulsed and potential devices for compensating (suppressing) pulsed noise arising in the power circuits of the active elements of these devices.

Known trigger containing two transistor switches connected by collector-base connections [1].

This trigger has insufficient noise immunity.

The purpose of the invention is to increase noise immunity.

To achieve the goal, a trigger transformer, an additional capacitor, and two additional resistors are introduced into a trigger containing two transistor switches connected by collector-base connections. One end of the first transformer winding is connected to the first lining of the additional capacitor, the second lining of which is connected to a common bus, and the other end of the first winding is connected to the power bus. One end of the second winding, consistent with the first winding, is connected to the end of the third winding, which is opposite with respect to the first winding, and connected to a common bus. The other end of the second winding through the first additional resistor is connected to the output of the first key, the other end of the third winding through the second additional resistor is connected to the output of the second key.

The drawing shows a schematic diagram of a trigger.

The device contains a symmetric trigger 1, the collectors of transistors 2 and 3 through resistors 4 and 5 are respectively connected to a power source 6, a pulse transformer 7 with two secondary windings 8 and 9 counterclockwise connected, the ends of which through resistors 10 and 11 are connected respectively to the power supply circuits of the transistor collectors 2 and 3. The beginning of the primary winding 12 of the pulse transformer 7 is connected to the potential clamp of the power supply 6, and its end through the electrolytic capacitor 13 is connected to a common bus of the device, to which keys start the secondary windings 8 and 9. The counting trigger input 14 is connected to the bases of transistors through decoupling diodes.

Consider the operation of the device in the following initial state. Transistor 2 is closed, transistor 3 is open (saturation mode) at the counting input 14 of flip-flop 1 low potential (logical “O”) is applied. When an impulse noise occurs in the common power circuit, this interference changes the potential of the collectors of transistors 2 and 3. One .... .............. s ......; temporarily, the same noise passes through the primary winding circuit 12 of the pulse transformer 7 (interference is isolated), the inverted pulse from one secondary winding 8 (the interference is separated and change sign) is fed through resistor 10 (converted in magnitude) to the point of connection of the power circuit to the collector of the transistor 2.

The second channel consists of a secondary winding 9, a resistor 11, and a connection point between the power supply circuit and the collector of transistor 3. Complete compensation for the effects of interference that changes the potential of the electrodes in the power supply circuits is achieved by the appropriate choice of the transformation coefficient of the pulse transformer 7 and the values of resistors 10 and 11. Electrolytic capacitor 13 included in the primary circuit 12 of a pulse transformer 7 for galvanic isolation.

Thus, the inclusion of a pulse transformer in the total power circuit of a symmetrical trigger with the number of secondary transformer windings in terms of the number of active circuit elements and the connection of the ends of these windings (for the circuit under consideration) with the connection point of the power circuit with the electrodes (collectors) of the active elements (transistors) of the circuit, and also the conversion of impulse noise in sign (primary - secondary winding) and amplitude (the number of turns of the secondary winding and the value of resistors 10, I) allows compensation

- »Identify the effect of interference that changes the potential of the electrodes of the active elements in the power supply circuits, thereby eliminating the unauthorized operation of the trigger when 5 pulsed interference occurs in the common power circuit.

Claims (1)

Claim A trigger containing two transistor 0 keys connected by collector-base connections, characterized in that, in order to increase noise immunity, a pulse transformer, an additional capacitor and two additional resistors are introduced into it, and one end of the first transformer winding is connected to the first the lining of the additional capacitor, the second lining of which is connected to the common bus, and the other end of the first 0 winding is connected to the power bus, one end of the second winding, which is consistent with the first winding, is connected is connected to the end of the third winding, which is opposite with respect to the first winding, and connected to a common bus, 5 the other end of the second winding is connected to the output of the first key through the first additional resistor, the other end of the third winding is connected to the output of the second key through the second additional resistor.