SU1504647A1 - Pulsed d.c. voltage stabilizer with current overload protection - Google Patents

Abstract

The invention relates to electrical engineering and can be used in power supply devices for automation units and computer facilities in which overvoltage of DC voltage regulators are possible. The purpose of the invention is to improve the accuracy of protection and improve the characteristics of the stabilizer. The goal is achieved in that the detection of a signal proportional to the load current is carried out over the area of the pulses at the output of the key element by integrating each pulse from the sequence, which makes it possible to determine the reliable value of the load current. 1 il.

Description

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The invention relates to electrical engineering and can be used in devices for power supply of automation units, computer equipment, in which overvoltages of a pulse voltage regulator are possible.

The goal is to increase protection accuracy and improve stabilizer performance.

The drawing shows a block diagram of a stabilized source with overload protection.

The stabilized DC voltage source contains a control unit 1 consisting of a key element 2 connected in series and an LCD filter diode 3, a throttle 4, a capacitor 5, a control unit 6, an input connected to the filter output, and an output to the first input of the circuit 7 matches, controlled by one-shot 8, an output connected to another input of the matching circuit 7, and an input to the output of block 9 of the comparison. The integrator 10 is input U, and U is connected to the output of the key element 2, and the output is connected to the first input of the comparison unit 9. The output 11 of the reference voltage is connected to the second input of the block 9. The output of the matching circuit 7 is connected to the key element 2.

The stabilized source works as follows.

In the nominal load mode, the control pulses from the code of the control unit 6 determine the duration of the pulses at the output of the matching circuit 7, and therefore the duration of the Open state of the key element 2. Each voltage pulse is from a sequence of pulses from the output

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Key element 2 enters the input of and, integrator 10, and integrates. The initialization of the Integrator to the beginning of the integration of the Subsequent pulse is performed by the same signals from the output of the key Element at the input U of the integrator. In this case, the presence of a pulse at the input U blocks the discharge circuit, and the absence of a pulse gives permission for the fast discharge of the integrator capacitor through the open transistor of the discharge circuit. The output voltage of the integrator, proportional to the area of the voltage pulse at the output of the key element, is fed to the first input of the comparison unit 9. The second input of the comparator unit 9 receives the voltage of the source 11, which is proportional to the maximum permissible load current. At nominal load, the voltage from Vigho7, and the source of the reference voltage exceeds the voltage at the integrator output, and there are no signals at the output of the comparator unit 9, as well as at the output of the controlled one-vibrator 8, which does not affect the operation of the device.

In the overload mode at the output of the control unit 6, the duration of the control pulses increases or a constant high logic level is present. In this case, the area of the voltage pulses at the output of the key element 2 increases and when the value exceeds the maximum permissible, the output voltage of the integrator 10, proportional to the area of the impulse at the output of the key element, will exceed the voltage of the source of the reference voltage 11, which causes the appearance of the signal at the output of the comparator block 9. A signal from the output of the comparator block 9 starts a controlled one-shot 8, which prohibits the necessary time of passage of control pulses to the input of the cell chevogo element 2 through the coincidence circuit 7 .74

Similarly, the current through the key element 2 is limited during the initial switching on of the pulse stabilizer, i.e. float is achieved.

Thus, in the proposed stabilizer, the protection accuracy is increased, since the signal proportional to the load current is determined by the area of the pulse at the key of the key element by integrating each pulse from the sequence, which allows determining the reliable value of the load current. In addition, limitations are imposed on the selection of the parameters of the LCD filter, the current is limited at initial power up, which improves the characteristics of the pulse stabilizers.

Claims (1)

Invention Formula A DC voltage regulator with overcurrent protection, containing a series-connected key element and an output bcb filter, a control unit, an input connected to the output of the LCD filter, a source of reference voltage, and an output connected to to the input of the comparator unit, characterized in that, in order to increase the accuracy of protection and improve the stabilizer characteristics, an integrator, a controlled one-vibrator coincidence circuit, and means for creating an inverse input are introduced into it Comparison, the integrator is connected to the output of the key element, and the output is connected to the inverted input of the comparison block, the output of which is connected to the input of the controlled single vibrator, output connected to the inverted input of the coincidence circuit, the direct input of which is connected to the output of the control unit, and output - to the control input of the key element.