SU112114A1 - Precision square pulse generator - Google Patents

Description

The subject of the invention is a precision square-wave generator used as a manipulator for special standard-signal generators and a sensor for square-wave pulses, as well as used for measuring telegraphic distortions in direct radio print channels.

The known schemes of rectangular pulse generators have an insufficiently high degree of accuracy of the generated pulses (pauses) in terms of their duration, which limits the range of their application.

The proposed precision pulse-angle generator largely eliminates this drawback, allowing it to be used in all those cases when periodic pulses with a specified duty cycle are required in terms of exemplary duration.

The method of constructing a precision generator of rectangular pulses is that the basis of the duration of the generated pulses are the periods of the exemplary frequencies of the quartz oscillator and a number of frequency dividers.

The conversion of periods of exemplary frequencies into pulses is performed using a trigger circuit with two stable states by applying trigger pulses marking the beginning and end of a period of exemplary frequency simultaneously to the anodes of the trigger lamp. In this case, the duration of the pulses and pauses is the same, i.e. the duty cycle is 0.5. Pulses with a doubled duration are removed from the second trigger, which is controlled by the trigger pulses of the first trigger. Pulses with a duty cycle of 0.25 are obtained from the third trigger, which receives trigger pulses from both the first and second triggers.

A precision square pulse generator emits pulses with a duration of: 0.2; 0.4; 1.0; 2.0; 4.0; 5.0; 20; 25; 125 and 250 digs with a duty cycle of 0.5 and 0.25 and at the same time, from another output, the pulses of double duration: 0.4; 0.8; 2.0; 4.0; 8.0; ten; 40; 50; 250 and 500 ms, with

No. 112114

duty ratio of 0.5. The error of the duration of the pulses or pauses between them does not exceed + (5 2 10) ms,

where t: is the pulse duration (pause). The pulse voltage is 15 volts across a resistance of several hundred ohms. The precision oscillator is powered from an AC mains voltage of 200-2308.

The trigger pulse (negative) is transmitted only at the moment when the half trigger, where the trigger pulses are taken, becomes conducting. Thus, the cathode follower receives pulses with a duty cycle of 0.5 from the first trigger; from the second trigger, pulses doubled in duration are received with a duty cycle of 0.5, and impulses with a duty cycle of 0.25 come from the third trigger.

The drawing shows the scheme of the proposed precision square-wave generator. The frequency of the crystal oscillator assembled on the lamp L is lowered by a number of trigger dividers with one steady state () and fed through a switch to the amplifier-limiter. From the output of the amplifier-limiter, after differentiation, the starting pulses arrive at the first trigger L13, which is triggered from each starting pulse, i.e. from the beginning and end of the period of the reference frequency. From the output of the first trigger, start-up impulses, which already have a two-fold lower repetition rate as compared to the start impulses given to the first trigger, are sent to the second trigger Lee, also triggered by each (starting) impulse. The third trigger trigger impulses come from both the first and second triggers. As a result of a similar supply of starting pulses, the third trigger produces pulses, to which there are pauses, equal in duration to three pulses.

Subject invention

A precision square-wave pulse generator, based on a master oscillator, stabilized by quartz, a series of trigger frequency dividers and an amplifier-limiter, characterized in that, in order to obtain accurate porosity values, the trigger ring of three triggers outputting pulses to each repeater from the first trigger with a duty cycle of 0.5, from the second one - doubled pulses with a duty cycle of 0.5, and from the third one - pulses with a duty cycle of 0.25.