SU1251297A1 - Pulser - Google Patents

Abstract

The invention relates to a pulse technique, in particular, to a device for forming pulses made on elements having an S-shaped volt-ampere characteristic (VAC), and can be used as a source of pulses. The purpose of the invention is to simplify and reduce the power consumption of a pulse generator, which is achieved by additionally introducing a second current supply element and a diode connected in parallel with the base-emitter junction of the bipolar transistor. The drawing shows a single-junction transistor 1, whose output I – V characteristic is S-shaped, resistors 2 and 5, negative power supply 3, positive power supply 4, diode 6, bipolar transistor 7, variable resistor 8, time specifying the capacitor 9. The change in the charge rate of the capacitor 9 and, consequently, the frequency of the generated pulses is produced by the resistor 8. 1 sludge. (+)

Description

The invention relates to a pulse technique, in particular, to a device for forming pulses made on elements having an S-shaped current-voltage characteristic (VAC), and can be used in equipment as a source of pulses.

The aim of the invention is to simplify and reduce the power consumption of the pulse generator.

The drawing shows the principal electrical circuit of the proposed pulse generator.

The pulse generator contains as a device with an S-shaped VAC one-junction transistor 1, the input characteristic of which is S-shaped (OPT), the first base of which through a resistor 2 is connected to the negative power supply bus 3, the second base - to the positive power bus 4 , and the emitter is connected via a resistor 5 to the power supply bus 4 and directly to the cathode of diode 6. The bipolar transistor 7 is connected to the OPT emitter 1 by a base, the variable resistor 8 to the collector to the power supply bus 4, and an electrode to the electrode specifying the second capacitor 9, the second plate of which is connected to the power supply bus 3.

When the power source is connected, the capacitor 9 starts charging in a circuit: positive bus 4 - resistor 5 - base-emitter junction of transistor 7 - capacitor 9 - negative bus 3. Base current of transistor 7 causes the appearance of a collector current and further charge of the capacitor 9 goes emitter current of the transistor 7, equal to the sum of the collector and base currents. At the same time, the ratio of the resistance values of the resistors 5 and 8 is selected in such a way that the transistor 7 is in a saturated state during the entire charge time of the capacitor 9. As the capacitor 9 is charged, the voltage across the emitter of transistor 1 increases, when it reaches the voltage level of the OPT 1, the latter turns on. The capacitor 9 is discharged along the circuit: diode 6 — emitter section — first base of transistor 1 turned on — resistor 2. In this case, the base-emitter transition of transistor 7 in the blocking direction is energized by the discharge current of capacitor 9

in the open diode 6. The transistor 7 is closed and the relatively low-impedance resistor 8 is disconnected from the discharge circuit of the capacitor 9. The resistance value of the resistor 5 is large enough and after the corresponding discharge of the capacitor 9 OPT 1 is turned off.

A new charge of the capacitor 9 begins through the resistors 5, 8 and the saturated transistor 7, and then the processes in the generator

are repeated.

The variable resistor 8 serves to change the charge rate of the capacitor 9, and hence the pulse frequency generated by the generator. In this case, the value of the minimum resistance of the resistor 8 can be up to p times less than the value of the resistance of resistor 5 (provided that the maximum condition of the transistor 7 is ensured during the charging of the capacitor 9), where p is the gain

Q current transistor 7 in the circuit with a common emitter.

As a device with an S-shaped IVC in the proposed pulse generator, in addition to a single junction transistor, a dynistor, the equivalent of a two-base diode, an avalanche transistor, and other devices can be used.

Claims (1)

Invention Formula A pulse generator containing a device with an S-shaped volt-ampere characteristic, connected by the first of its terminals to the first power supply bar, the second to one of the terminals of the first current supplying element, the time setting of the capacitor connected to one of the plates to the first power bus, and the bipol A transistor, characterized in that, in order to simplify and reduce power consumption, a second current supply element and a diode, connected counter-parallel to the base-emitter tary transition of the bipolar transistor, are introduced, the emitter b the polarity of the transistor is connected to another plate, the time of the capacitor is wired, the base is connected to the second of the terminals of the S-shaped Wilt-ampere characteristic of the device, and the collector is via the second5 Circuits of the current-giving element - with the second power bus, to which another output of the first current-creating element is also connected.