SU1557549A1 - Stabilized power source - Google Patents

Abstract

The invention relates to electrical engineering and can be used in the development of stabilized power sources for electronic devices. The aim of the invention is to provide protection against overload current load and simplify the circuit implementation while maintaining the minimum and constant static error of the output voltage. With an increase in the load current measured by the current sensor 6, above the set value of the threshold element 7, the frequency of the pulses from the current converter 8 decreases. This reduces the duty cycle of the power switch 1 and thus limits the magnitude of the load current, i.e. overcurrent protection is provided. The simplification of the circuit consists in using a reversible binary pulse counter 9 of pulses as a pulse width modulator. Digital pulse-width modulation provides high quality stabilization and constant static error in the output voltage. 3 il.

Description

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The invention relates to electrical engineering and can be used in the development of stabilized power sources for radioelectronic devices, especially digital computing systems and data transmission systems.

The aim of the invention is to provide protection against overload current load and simplify the circuit implementation while maintaining the minimum and constant static error of the output voltage.

FIG. 1 is a functional diagram of a stabilized power source; and in fig. 2 and 3 are graphs of the frequency of the pulses versus current and voltage, respectively, of the current-frequency converter and the voltage-frequency converter.

The stabilized power supply (FIG. 1) contains a series-connected power switch 1 and an LCD Filter 2, the output of which is connected to the output terminals. Comparator 3 is connected by the first input to the output pins, the second input to the reference voltage source 4, and the output to the control input of the voltage converter 5 in the pulse frequency. The resistive current sensor B is connected between the input output and the free power output power switch 1. The threshold element 7 is connected to the output pins of the resistive current sensor b, and the output to the control input of the current converter 8 to the frequency of the pulses, the output connected to the summing input of the reversible binary counter 9 pulses, subtracting Its input is connected to the output of the voltage converter 5 to the pulse frequency, and the output to the control input of the power switch 1. The frequency of the current converter 8 to the frequency of the pulses is constant to the current threshold value and decreases with increasing current (Fig. 2) The device works as follows.

When the supply voltage is turned on, the current-to-frequency converter 8 operates and outputs a sequence of pulses with a constant frequency (Fig. 2), while the reversible counter 9 closes the power switch 1. As the output voltage rises, the frequency of the pulses from the voltage converter 5 increases wives Reversible counter 9 in

The dynamics are carried out by the pulse-width modulation of the state of the power switch 1.

As soon as the load current becomes larger than the setting I P0p of the threshold element 7 (Fig. 2), the frequency of the pulses from the current converter 8 decreases, the duty cycle of the power switch 1 eventually also decreases and thus the load current is limited, i.e. . overcurrent protection is provided. With a decrease in current less than IП0р key 1 continues to work normally.

The circuit can work as a pulse current regulator, for which comparator 3 is excluded from the circuit, and the source 4 of the reference voltage is connected to the input of the converter 5. The current to be stabilized is set by selecting the threshold element setting (choosing Ip0p). An introduction to the pulse-width digital modulator of the current control loop allows simple and effective protection against current overloads. At the same time, the range of the limited current is wide: from O, II P0p to If, 0p. Current protection is especially important when designing power supplies for data transmission systems,

The device has greatly simplified the circuit implementation, since instead of the analog-to-digital converter and the pulse-width modulator, a reversible counter is used that provides digital pulse-width modulation. This ensures high quality stabilization and a constant static error of a stabilized quantity.

Claims (1)

 Invention Formula A stabilized power supply comprising a power switch connected in series and an LCD filter whose output is connected to the output pins, a binary pulse counter, a reference voltage source, and a voltage to pulse frequency converter, characterized in that in order to provide overcurrent protection load and simplify the circuit implementation while maintaining the minimum and constant static error of the output voltage, a resistive current sensor is inserted into it ka, threshold element, current converter to pulse frequency and comparator, and a reversive binary pulse counter is used as a binary counter, with a resistive current sensor connected between the input terminal and the free power output of the power switch, the threshold element is connected to the terminals of the resistive current sensor and the output to the control input of the current-to-pulse converter, the frequency of which is constant threshold TLSR FIG. 2 the magnitude of the current decreases with increasing current, the comparator is connected to the output terminals by the first input, to the reference voltage source by the second input, and to the control input of the voltage converter into the pulse frequency output connected to the subtracting input of the reverse binary counter, the summing input which is connected to the output of the current-to-pulse converter and the output to the control input of the power switch. but Figz