SU723762A1 - Controlled generator - Google Patents

Description

I

The invention is intended for use in radio-frequency installations for various purposes, in particular in electrical measuring equipment.

A controlled oscillator is known, which contains a series RC circuit, a source of control voltage, and a semiconductor pentode, connected to a capacitor discharge circuit, the time at the end of the RC circuit ij. The generator frequency is varied by varying the voltage of the control voltage source. In this way, you can adjust the frequency of the generator within one decade

The aim of the invention is to expand the range of the electronic adjustment of the following pulse frequency.

This is achieved by the fact that a generator containing a series RC circuit, a source of control voltage, a semiconductor pentode, including in the capacitor discharge circuit the time of the output RC circuit, which in time specifies the PC circuit,

the p-ptransistor is connected in series, the emitter of the transistor is connected to the resistor of the master circuit of the C circuit, the collector to the capacitor of the master circuit of the R C circuit, and the base is connected to the second emitter of the pentode and to the common busbar.

The drawing shows an electrical circuit of a controlled generator.

The controlled oscillator contains an RC driving circuit, consisting of resistor 1 to capacitor 2, transistor 3, bias resistor 4, limiting resistor 5, semiconductor pentode 6, control voltage source

(EupR.)

When connecting the power source

starts to charge; The charging current is determined by the collector current of the transistor, which in turn depends on the voltage applied to its base. Consequently, by increasing the voltage of the control voltage source, the collector current of the transistor decreases. The frequency of all the 5X pulses of the generator decreases. At the same time, as the voltage of the control voltage source increases, the threshold value of the pentode switch-on voltage increases, which also leads to a decrease in the frequency of the generator output pulses. The introduction of a bias resistor makes it possible to form (together with a resistor of limit 5) a voltage divider that provides the transistor in the active region.

Using the new elements of the transistor and the mixing resistor favorably distinguishes the previous controlled oscillator from the known one, since the trans; setting the output pulse frequency is carried out within a decade

Claims (1)

1. USSR author's certificate number 493000, cl. N OZ K 1/16, O2.O9.75 (prototype). -® five S tt / np