SU838681A1 - Switch-type voltage stabilizer - Google Patents

Description

one

The invention relates to electrical engineering and can be used in power supply devices for automation equipment and computer technology.

The key voltage regulators are known that contain a key element, the input connected to the input terminal, and the control input to the output of the control unit, the input of which is connected to the output, in parallel with which the capacitor 1 and 2 are connected.

The disadvantage of these stabilizers is due to the application of the key principle of voltage stabilization and is to increase the voltage ripple on the load or the mass-dimensional parameters of the filter for a given ripple factor, while increasing the difference between the nominal input and output stabilizer voltages. In addition, the input power source is loaded with a large current (several times greater than the load current) when charging the capacitance of the filter capacitor.

The purpose of the invention is to reduce the output voltage ripple and charge current of the output filter capacitance.

key constant voltage stabilizer.

The goal is achieved by connecting an additional capacitor between the output of the key element and the output terminal, which is smaller in capacitance than the output capacitor with an additional key element connected in parallel, the control input of which is connected to the output of the control unit in antiphase with the main key element .

Figure 1 shows the scheme of the proposed stabilizer; Figure 2 shows graphs illustrating the principle of operation of the stabilizer.

The voltage regulator contains a source of 1 constant voltage,

0 to which the internal resistances 2 of a constant voltage source 1 and a switch 3, a switch 3, a capacitor 4 with a switch 5 connected in parallel are connected in series

5 and load 6 with a parallel-connected capacitor 7 of the output filter. The input of the control unit 8 is connected in parallel with the load 6, and the output to the keys 3 and 5. In this case, the control unit 6 ensures the operation of the keys 3 and 5 in antiphase, and the voltage on the load is stabilized along the feedback circuit from the load b through the unit 8 controls for keys 3 and 5. The stabilizer operates as follows. When the input voltage U is applied, the voltage U at the load b is absent and the control unit 8 switches on switch 3 and turns off switch 5. At the same time, capacitors 4 and 7 are charged through resistance 2. After charging the capacitors 4 and 7, the current does not flow through the circuit and the capacitors 4 and 7 are set to voltage, the sum of which is equal to the input voltage Q. After that, the control unit 8 turns off the key 3 and turns on the key 5. Capacity 7 is discharged load G, and capacitance 4 through switch 5. After the capacitor 7 is discharged to load 6 to a predetermined voltage, the process is repeated. The assumption made that the load b does not affect the charge of the capacitors of capacitors 4 and 7 slightly affects the accuracy of the calculation, but allows us to more clearly present the operation of the filter. FIG. Figure 2 shows the graphs of voltage changes during operation of the voltage stabilizer for the frequency case: the capacitor 4 capacitance is less than the capacitor capacitance and the charge-discharge constant of the capacitor 4 capacitance is less than the constant charge-discharge capacitance of the capacitor 7. When the input voltage is applied the voltage Uxt (time to) through the capacitance of the capacitors 4 and 7 a current flows through the field. Since the time constant of the charge of the capacitor 4 capacitance is less than the constant charge time of the capacitor of capacitor 7, the capacitance of capacitor 4 is charged faster than the capacitor of capacitor 1, which determines the time t fixing a decrease in the charge current to zero , and the distribution of voltages on the capacitors 4 and 7, respectively, are equal to U and.y, and m and id + and; At the time t, the control unit S turns off the key 3 and turns on the key 5. Since the discharge time constant the capacitor capacitance 4 is less than the constant time of discharge of the capacitor capacitance 7, then the capacitance of the capacitor 4 through the key 5 is discharged to zero (time t). while the capacitance of the capacitor 7 is discharged from the load 6 to the voltage and. After discharging the condensate capacity 4, the control unit 8 turns off the key and turns on the key 3 (for example, at time 1 "). Since the capacitor 7 capacitance is charged before the voltage and, during the charging time of the capacitor 4 (tj to tj.) it is charged before the voltage Ua and the capacitance of the capacitor 4 - before the voltage. Moreover, the equality UU + U is maintained. The equality U is maintained. In the future, the stabilizer works in the same way. Since the discharge time of the capacitor 4 capacitance is determined only by the internal resistance of the key 5 and is constant, the average voltage on the load Yc is controlled by the time the capacitor 7 has discharged the capacitance to the load 6 to a predetermined voltage. Thus, the amplitude of the voltage on the capacitor 7 capacitance changes during the operation of the voltage stabilizer when exposed to destabilizing factors from and, o Uy. Since the voltage U7 on the capacitor 7 capacitance is part of the input voltage U of the stabilizer, the ripple amplitude of the voltage U7 on the capacitor 7 capacitance is always less than the input voltage amplitude and, and therefore less, the voltage ripple on the load compared to the known voltage stabilizer. The decrease in consumed currents from a constant voltage source during the charging of capacitors is explained by the well-known formula for the dependence of the charging current on the capacitance and the rate of change of the voltage f - dUc s - dt where i is the charging current of the capacitors 4 and 7; c is the equivalent capacitance of series-connected capacitors 4 and 7; rate of change of voltage equivalent capacitance. Formula. - the invention The key voltage regulator containing the main key, the input connected to the input terminal and the control input - to the output of the control unit, the input of which is connected to the output terminals, in parallel with which the main capacitor is connected, in order to reduce output pulsations voltage and current charge. capacitance of the filter capacitor, between the output and the output terminal is included introduced additional capacitor, the capacity of which is less than that of the main capacitor, parallel to the additional a connected capacitor is connected

a key whose control input is connected to the output of the control unit in antiphase with the main key element.

Sources of information taken into account in the examination

1. Alexander F.I., Sivakov A, R. Pulse converters and stabilizers. L., Energie, 1970, p. 12, ris.1,3.

2. Graver E.S. Key DC Voltage Regulators.

M., SV, 1970, p. 10, fig. 1.3.

W / L

and d.2

Claims (1)

Formula. inventions A key voltage regulator containing a main switch connected to the input terminal by an input and a control input to the output of the control unit, the input of which is connected to output terminals, the main capacitor is connected in parallel, characterized in that, in order to reduce ripple of the output voltage and charge currents the capacitance of the filter capacitor, between the output of the switch and the output terminal, the added additional capacitor is included, the value of the capacitance of which is less than that of the main capacitor, parallel to the additional condensers connected inputted key, the control input of which is connected to the output of the control unit in phase opposition with the main key element.