SU834829A1 - Pulse generator - Google Patents

Description

(54) PULSE GENERATOR

one

The invention relates to a pulsed technique and can be used in electronic devices of automation, remote control and computing.

Known pulse generator containing transistors of different types of conductivity and two RC circuits 1.

The disadvantage of the generator is the long duration of the fronts of the output pulses.

A pulse generator is known that contains two transistors of different conductivity types, two capacitors, three resistors, the emitters of both transistors are connected, the collector of the first transistor is connected to the base of its transistor through the second resistor, and to the base of the second capacitor transistor, the collector of the second transistor is connected to the common bus directly, through the third resistor - with the base of its transistor and through the second capacitor - with the base of the first transistor 2.

The disadvantage of this generator is that the maximum amplitude of the output pulses (maximum supply voltage) cannot exceed the sum of the maximum allowable reverse voltages of the emitter-base (for most silicon BbicoK04acTOtHbix transistors equal to 3-4V), since this leads to reverse current emitters and accelerated charge capacitors.

The purpose of the invention is to increase the amplitude of the pulses and reduce the duration of the back edge of the pulses.

This goal is achieved by the fact that

a pulse generator containing two transistors of different types of conductivity, two capacitors, three resistors, the collector of the first transistor being connected through the first resistor to the base of its transistor, through the second resistor to the bus

power supply and through the first capacitor - with the base of the second transistor, the collector of the second transistor is connected to the common bus, through the third resistor - with the base of its transistor and through the second capacitor - with the base of the first transistor, a diode connected between the emitters of the transistors is inserted.

The drawing shows a circuit diagram of a pulse generator.

The pulse generator contains the first transistor 1 reverse conduction, the second transistor 2 direct conduction, diode 3, two consecutive times driving the KS circuit, executed respectively on the first and second capacitors 4 and 5 and the first and third resistors 6 and 7, the load resistor 8. The pulse generator is powered from the power bus 9, the generator has an output of 10.

The pulse generator works as follows.

When the power is turned on, the time setting capacitors 4 and 5 are discharged, transistors 1 and 2 and diode 3 are closed, since both emitter junction transistors and a diode are shifted in the opposite direction, the potential at output 10 is almost equal to the supply voltage. When the time setting capacitors 4 and 5 charge through time, the setting resistors 6 and 7 are more than half the supply voltage, the emitter junction and the diode will shift in the forward direction, which will lead to the opening of transistors 1 and 2 and diode 3. Collector current of transistors will create a voltage drop across the load resistor 8, which will reduce the voltage between the collectors of the transistors, and the voltage across the capacitors cannot change instantaneously and will become much larger than half the voltage between the collectors of the transistor. This will lead to even greater opening of both transistors and the emergence of an avalanche-like process, leading to saturation of transistors 1 and 2 and reducing the potential at output 10 to almost zero.

Capacitors 4 and 5 bits are opened through open transistors 1 and 2 and diode 3, the TopBie will close, leading to an increase in potential at output 10 before the supply voltage and the circuit will return to its original state, a new capacitor charge cycle will begin.

Turning on the diode reliably protects the emitter transitions of the transistors from breakdown, extends the amplitude range of the output pulses upward, improves the back edge of the pulses, which allows you to create a pulse generator whose amplitude can reach hundreds of volts with the use of appropriate transistors and a diode.

Claims (2)

Invention Formula A pulse generator containing two transistors of different types of conductivity, two capacitors, three resistors, the collector of the first transistor connected through the first resistor to the base of its transistor, through the second resistor - with a thickness power supply and through the first capacitor - with the base of the second transistor, the collector of the BTOJ of the transistor is connected to the common bus directly, through the third resistor - to the base of its transistor and through the second capacitor - to the base of the first transistor, characterized in order to increase the amplitude of pulses and reducing the duration of the trailing edge of the pulses; a diode connected between the emitters of the transistors is inserted into it. 0Sources of information taken into consideration in the examination of 1 USSR Author's Certificate No. 432664, cl. H 03 K 3/26, 1972. 2. USSR author's certificate in application number 2027626 / 18-21, cl. H 03 K 3/02, 5 05.23.74. . four yes -l. five ABOUT