SU388357A1 - - Google Patents

Description

PULSE SEQUENCE GENERATOR

one

The invention relates to the field of computing and can be used to generate a sequence of pulses and generate time delays.

The well-known pulse train generator, which contains series-connected inverters with time master circuits at the inputs, has a large error in setting the time interval between the last pulse of one period and the first pulse of the subsequent period.

The purpose of the invention is to reduce the error in setting the time interval between the last pulse of one period and the first pulse of the next period.

For this purpose, a multivibrator is introduced into the proposed pulse train generator, the output of which is connected to the output of the master circuit of the first of a series of series-connected inverters. The control input of the multivibrator is connected through a resistor to the emitter of the transistor of an additionally introduced emitter follower, the input of which is connected to the output of the last of a series of series-connected insepTopOBs.

Ma FIG. 1 shows the scheme of the proposed pulse sequence generator; in fig. 2 are voltage diagrams, where L / EX and t / are the output voltages at the input and output of the inverter, and

the digit with t / Bx and f / out corresponds to the number of the inverter.

Inverters 1- / p + 1 are connected in series. The input to the inverters 1-ln + i includes the time specifying .RC-chains, consisting of capacitors 2-.2n + i and resistors connected to bus 4 of the power supply. The first two inverters / and L form a multivibrator, the control input of which through a resistor 5 is connected to the emitter of the transistor 6, connected to the emitter follower circuit, the input of which is connected to the output of the last inverter / n + 7, 8 c N - sequence generator outputs

pulses.

The circuit should be designed in such a way that the oscillation period of the multivibrator formed by the first two inverters / and L when the voltage at the base of transistor 6 is equal to zero is greater than the required period of the pulse sequence for any variation of the parameters of cells formed by the inverters 1-Ln- i. After termination of the pulses at the output N

a pulse appears at the output of the inverter / n + i, and, therefore, at the base of the transistor 6. This pulse discharges the capacitor 2i to the voltage unlocked the inverter li, and the discharge time of the capacitor through the transistor 6

many times less than the time of its discharge through the resistor 3i at the exponent site, where the period of the main generator is adjusted. Therefore, the time interval between the end of the pulse at the output N and the beginning of the pulse at the output 7 is less than the same time.

In such a generator of a pulse sequence at the initial moment when the inverter Ji is open, there is practically no feedback from the output to the ring of the oscillator, because the transistor 6 is reliably closed with a positive potential at the emitter at zero potential at the base.

Therefore, impulse noise arising in the chain of inverters is not received again at the input of this chain. At the same time, due to the large inertia (long oscillation period) of multivibrators on inverters 1 and li, it is much more resistant to the effects of impulse noise on the power buses than cells that generate separate pulses.

When the inverter / i is locked by a large negative potential, the short-term impulse noise that occurs in the chain of inverters does not significantly affect the discharge time of the capacitor 2i.

The state of the multivibrator can be changed by a relatively large amplitude and duration pulse generated by the cell / n + b and only at the moment close to completion of the closed state of the inverter h, i.e. when the charge of the capacitor 2i is relatively small.

Subject invention

Pulse sequence generator, containing series-connected inverters with time master circuits at the inputs, characterized in that, in order to reduce the error in setting the time interval between the last pulse of one period and the first pulse of the subsequent period, a multivibrator is introduced into the pulse sequence generator, the output of which is connected to the output the time of the master of the first of a series of consecutively created inverters, and the control input connected via a resistor to the emitter of the trans a resistor of an additionally introduced emitter follower, the input of which is connected to the output of the last of the mentioned series of series-connected inverters.