RU2014729C1 - Pulse oscillator - Google Patents

Abstract

FIELD: pulse engineering. SUBSTANCE: oscillator has a circuit which comprises control switch, alternative resistor, winding of electromagnet relay, and capacitor connected in series. Common output of a winding of the electromagnet relay and capacitor is connected with anode of a diode and leads for connecting with a load. One output of a closing contact, which is made of a read relay, is connected with the common output of the capacitor, alternative resistor and control switch. The second alternative resistor is connected between cathode of the diode and output of the read relay used as a closing contact. The contact is coupled with the lead for connecting with the load. Movable contact of the alternative resistors are common. EFFECT: stabilized bearing voltage. 2 dwg

Description

 The invention relates to a pulse technique and can be used as a generator of rectangular pulses of adjustable duty cycle and frequency in electrical circuits of signaling, automation, control and management of technological and other equipment.

 A generator is known in which a sealed contact reed switch sensitive to electromagnetic effects is used as a voltage and current interrupter. The generator consists of series-connected elements: plus bus, control key, variable resistor, inductor, rectifier diode, load resistance and negative bus. In parallel to the variable resistor and coil, a capacitor is connected, creating together with them an adjustable resonant circuit, and in parallel to the resistor, coil and diode, the contacts of the reed switch are connected.

 The disadvantages of this generator are the dependence of the frequency on the load resistance (frequency-dependent) and when the resistance in the resonant circuit decreases, the reference voltage on the load increases, while the pulse amplitude is significantly distorted, which limits the use of the generator in some electronic pulse devices.

 The purpose of the invention is the stabilization of the reference voltage allocated to the load during the adjustment of the pulse frequency.

 This is achieved by the fact that in the design of the generator an additional variable resistor is introduced, similar to the resistor installed in the resonant circuit and mechanically connected to it (on one rotary shaft).

 In FIG. 1 shows a schematic diagram of the proposed generator with a dual variable resistor; in FIG. 2 (a, b, c) - characteristics of the change in the reference voltage at the load.

 The circuit contains series-connected elements: a control key 1, a variable resistor 2, an inductor 3, a diode 4, a variable resistor 5 connected to the load 6 and the second terminal of the reed switch 7 by the first output to the cathode of the diode 7. In parallel, the resistor 2 and capacitor 8 is connected to coil 3, and reed switch contacts are connected in parallel to resistor 2, coil 3, diode 4 and resistor 5.

 When adjusting the frequency of the generator with resistor 2, the reference voltage (at the time of pause) on the load remains unchanged (b), since the resistance on resistor 5 changes inversely with the resistance of resistor 2.

; LC=(Т/2π)²;
f_и=

=

, где q =

- скважность импульсов;
Т_кк - период колебания в резонансном контуре;
π=LC·(U_R) - постоянная времени контура;
U_вх ˙ С - постоянная времени заряда конденсатора входным напряжением; откуда t_и=LC (U_вх) - длительность импульса при R=0.The amplitude, shape and duration of the pulse emitted at the load are determined by the magnitude of the input voltage and the characteristics of the resonant circuit, with a certain threshold voltage for switching the contacts of the reed switch on and off. If the inductance of coil 3 of the circuit is large enough with respect to the sensitivity of the reed switch, then this threshold voltage (or current rather) can be neglected in the calculations, then
T _kk ≈ T _n = 2

; LC = (T / 2π) ² ;
f _and =

=

where q =

- duty cycle of pulses;
T _kk - period of oscillation in the resonant circuit;
π = LC · (U _R ) is the time constant of the circuit;
U _I ˙ C is the time constant of the capacitor charge by the input voltage; whence t _and = LC (U _in ) - pulse duration at R = 0.

Udt ; U_д=

=

.Thus, the average value of the pulse voltage at the output of the generator can be calculated according to well-known formulas, where U _and is the average value of the voltage during the duration of the pulse, equal to the average value of the input voltage,
U _cp =

Udt; U _d =

=

.

 How to calculate a parallel resonant circuit is also known. An additional constructive solution will make it possible to obtain more stable pulses close to a rectangular shape at the output of the generator if a constant stabilized voltage is applied to the input, and as a result, an extension of the functionality and scope of application.

Claims (1)

 PULSE GENERATOR, comprising a circuit connected to the positive power bus from a control key, a variable resistor, an inductor and a diode connected in series, a capacitor connected in parallel to the inductor and a variable resistor, the first output of the reed switch connected to the common terminal of the variable resistor, control key and capacitor, characterized in that, in order to stabilize the reference voltage released on the load while adjusting the frequency of the output pulses, the second variable second resistor connected between the cathode of the diode and the second terminal of the reed switch connected to the terminal for connection to the load, wherein the movable contacts of variable resistors are mechanically joined.

Images