SU1411932A1 - Generator of symmetrical square pulses - Google Patents

Abstract

The invention can be used in the secondary stabilized sources of electronic equipment. The goal of the invention — to improve the stability of the symmetry of the output pulses — is achieved by balancing the positive and negative output pulses. For this, the second comparator 2, the second capacitor 4, the second 8 and the third 9 resistors and zener diodes 10-12 are additionally introduced into the generator. The drawing also shows the first comparator 1, the first capacitor 3, the voltage divider on resistors 5 and 6, the first resistor 7, the first 13 and the second. 14 output bus, common bus 15 and power supply 16. With the help of the second capacitor, automatic balancing of the output pulses takes place. Zener diodes 10 and 11 ensure the stability of the generation frequency. 1 il. i (L

Description

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I The invention relates to a pulse technique and can be used in secondary stabilized power supplies, electronic equipment 1,

 The purpose of the invention is to increase the stability of the symmetry of the output pulses by balancing the positive and negative output pulses.

The drawing shows a circuit diagram of a generator of symmetric rectangular pulses.

The generator contains the first 1 and second 2 comparators, the first 3 and second i capacitors, the resistive voltage divider on resistors 5 and 6, the first 7, the second 8 and the third 9 resistors are left 10, the second 11 and the third 12 hundred polaritons, the first 13 and the second 14 you-:: one tires, a common bus 15 and a power source 16.

The outputs of Comparators 1 and 2 are connected respectively to buses 13 and 14. The output of comparator 1 is connected via resistor 7 with its inverting input and through capacitor 3 to resistor 5 and with a non-inverting input of comparator 2, the inverting input of which is connected to the output of comparator 1 and resistor 6, the midpoint of the connection of resistors 5 and 6 is connected to the non-inverting input of comparator 2. The Zener diodes 10 and 11 are connected in series to each other and connected to the first bus of the power supply 16 via a resistor 8. The average connection point of the Zener diodes 10 and 111 is connected via capacitor 4 to the n | inverting input of the comparator 21. The Zener diode 12 is connected between 15 and the second bus of the power supply 16, and through a resistor 9 s | Habilitron 12 is connected to the first bus of the power supply 16.

The generator works as follows.

When the supply voltage is applied to the output of the comparator 1, it generates rectangular pulses, and at B1 of the comparator 2, rectangular pulses of opposite polarity. The polarity of these pulses with respect to the Hijuo to the minus bus of the source 16 of the reel is always positive due to the axial voltage across the comparators.

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The output pulses of the generator must have the same duration. The main cause of asymmetry of the output pulses (difference in duration) is the difference in the amplitudes of the positive and negative pulses at the output of the comparator 1 relative to the average power point of the comparators 1 and 2. This is a consequence of the inequality of the positive and negative voltages of the comparators 1 and 2. the absolute value as well as the residual voltages on the elements of the comparator 1. The difference of the amplitudes of the positive and negative pulses on the output of the comparator 1 leads to an inequality of the charge currents (conventionally chosen for a positive voltage at the output of the comparator 1) and overcharging (with a negative voltage at the output of the comparator 1) of the capacitor 3 through the resistor 7. Suppose that the amplitude of the positive pulse at the output of the comparator 1 is larger in absolute value than the amplitude of the negative pulse (the voltage is positive power supply, or less residual voltage at the output elements of comparator 1), then the charging current of capacitor 3 will be greater in absolute value of the recharge current of capacitor 3. The charging current passes through the circuit: output of comparator 1, resistor 7, capacitor 3, , capacitor 4, zener diode 11, the source bus 16 n - is negative. The charging current passes through the circuit: positive bus of source 16, pi, tani, resistor 8, zener diode 10, capacitor 4, capacitor 3, resistor 7, output of comparator 1, resulting in a constant component on capacitor 4 and the average power point of the comparators 1 and 2 will shift towards decreasing the voltage of the positive power source, i.e. the amplitudes of negative and positive pulses at the output of comparator 1 will become equal in absolute value. With an increase in the amplitude of the negative pulse of the comparator 1 on the capacitor 4, the constant voltage component and the average power point will shift towards decreasing the voltage of the negative power source.

Consequently, using a capacitor 4 n {the automatic balancing of the output pulses of the generator is found. Automatic balancing of output pulses occurs both when the supply voltage and residual voltages are spread across the comparator 1 elements, and when exposed to destabilizing factors (changes in ambient temperature, supply voltages, parameters of circuit elements during their aging, etc.). Zener diodes 10 and 11 ensure the stability of the generator power supply and thus the generation frequency stability.

Claims (1)

Invention Formula A symmetric rectangular pulse generator containing the first comparator, the output of which is connected to the first output bus and through the first resistor to the inverting input and one of the output of the first capacitor, non-inverting the input of the first comparator is connected to the midpoint of the resistive voltage divider, one of the conclusions of which connected to the output of the first comparator, characterized in that, in order to increase the stability of the parameters of the output pulses, a second comparator, a second capacitor, a second and a third resistors and three Zener diodes, the first and a Zener diode are connected in series to each other and connected through the second resistor to the first power supply bus, the middle connection point of the zener diodes through the second capacitor is connected to the second inlet: the first capacitor, to the second output of the resistive voltage divider and to the non-inverter named the second comparator input, the inverting input of which is connected to the output of the first comparator, and the output of the second comparator is connected to the second output bus, the third zener diode is connected to the second source power bus, the cathode to the common bus and via the third resistor to the first power source bus The anode of the first and the cathode of the second zener diode are connected to the corresponding supply circuits of the comparators.