SU964594A1 - Discrete voltage regulator - Google Patents

Description

(3) DISCRETE VOLTAGE STABILIZER

one

The invention relates to electrical engineering and can be used to stabilize the power supply voltage of electronic equipment.

A device comprising a partitioned secondary winding, semiconductor switches, booster transformer, sensor, control unit and associated connections 1., Q is known.

A device is known comprising a power transformer with a partitioned primary winding, a booster transformer, semiconductor switches, a comparison unit, a circuit, 5 controls, and a corresponding communication 2.

A common drawback of the known devices is the large distortion of the shape of the output controlled voltage, 20, which is due to the use in them of only one unit compared (in the first sensor device) of the output adjustable and reference

voltages generating output signals; Output voltage output output

above the reference stress

voltage is less than the reference voltage.

The closest to the proposed technical essence and the achieved result is a device containing two threshold elements, a sectioned-winding autotransformer, switching elements and the corresponding connections 3.

However, the automatic voltage regulator has a limited range of adjustment, determined by the circuit design of the known device; the maximum number of switching windings of the autotransformer is three. Moreover, when switching the windings of an autotransformer in a known device, there is a brief interruption of the power supply at the load at the moment of switching the relay contacts controlled by the first and second threshold elements. If we assume that there are no interruptions in the power supply, i.e. the contacts of the Two relays operate simultaneously, inevitably at. Circulation of circulating currents, causing premature destruction of the con- tacts, cycles of the relay or windings of autotransformers.

In addition, in the known device, it is impossible to disconnect the voltage applied to the load when the input voltage goes beyond the control limits.

The aim of the invention is to expand the range of output voltage control, to eliminate power interruptions when switching over transformer leads and. ensuring that the regulator is turned off when the regulated voltage exceeds the specified limits. ,

The goal is achieved by the fact that in a discrete voltage regulator containing a transformer, the first tap of the primary sectioned winding of which is connected to the first input of the stabilizer, the switching elements, the first and second threshold elements, the switching elements are divided into the main group and the group of | the second input of the stabilizer is connected to the first inputs of the switching elements of the main group and through the ballast resistor to the first inputs of the switching elements of the auxiliary group, the output of the first switching element of the main group is connected to the last tap of the primary winding of the transformer connected to the output of the corresponding commuting element of the auxiliary group and with the corresponding tap of the primary The first winding of the Transformer, parallel to the secondary winding of the transformer and the output of the stabilizer include the first and second threshold elements, the outputs of which are connected to the inputs of the inserted control unit, each of which is connected to the control input of the corresponding switching element.

FIG. 1 shows a block diagram of a discrete voltage regulator; in fig. 2 and 3 - timing charts of the control unit

.8 modes for increasing and decreasing the output voltage, respectively.

The discrete voltage stabilizer contains the first 1 and second 2 threshold elements., A group of 3 main switching elements, a group of 4 auxiliary switching elements, a ballast resistor 5, a power transformer. 6, a control block 7, input pins 8 and 9, and output conclusions 10. and 1.1.

The first input terminal 9 of the stabilizer is connected to the first tap of the primary sectioned winding of the power transformer 6, the second (8) with the first inputs of the switching elements 12.1, 12.2, ...., 12.N of main group 3 and through the ballast resistor 5 with the first inputs of the switching elements 12. N-1, 1 2. N-2, ..;,. 12.2N-1 auxiliary group. The output of the first switching element 12.1 of the main group 3 is connected to the last tap of the primary winding of the transformer 6., the output of each of the other switching elements 12.2, 12..3 ,. . . 12.N of main group 3 is connected to the output of the corresponding switching element of auxiliary group 4 and to the corresponding tap of the primary winding of the transformer 6. Parallel to the secondary winding of the transformer 6, the first and second threshold elements are included. 1 and 2, the outputs of which are connected to the inputs of the control unit 7. Each of the outputs 13.1, 13.2, ..., 13.2N-1 of the control unit 7 is connected to the control input of the corresponding switching element.

The threshold element 1 is for setting the lower limit of the output regulated voltage, the threshold element 2 is for setting the upper limit of the output adjustable voltage.

Threshold elements 1 and 2 can be made in the form of voltage comparators on integrated circuits ...

The switching elements of the main and auxiliary groups 3 and 4 are designed for switching the leads of the primary sectioned winding of the transformer 6 and can be made in the form of relays, thyristors, high-voltage transistors.

Claims (3)

The control unit 7 is designed to generate control signals for the switching elements 12.1, 12.2N-1. The discrete voltage regulator works as follows. When the power supply is turned on, the control unit 7 generates a signal at the output 13.1 and connects the switching element 12.1 of the main group 3 of the switching elements, which is the minimum possible voltage at the output terminals 10 and 11 of the device. Power transformer 6 is designed in such a way that when switching on the switching element 12. 1 voltage at the output pins 10 and 11 or below the permissible, or not within the specified limits. After switching on the supply voltage, three modes of operation of the stabilizer are possible. First, if the output voltage is within the set limits, the error signals from the threshold elements 1 and 2 are not received. The second, if the output voltage is below the allowable one, receives the error signal from the threshold element 1. The third, if the output voltage. above the allowable, pacco lacquering signal comes from threshold element 2.. In the first mode, the stabilizer is in a stable state, in the insensitivity region, switching of the transformer windings does not occur. The insensitivity region of the stabilizer is determined by the difference between the set thresholds of the voltages of the elements 1 and 2. The voltage difference is chosen depending on the required TO: Stability. At the same time, the condition I / i should be satisfied, where dl) is the voltage between adjacent power taps. transformer; and, and are the voltage thresholds of elements 1 and 2, respectively. . Consider the work of the stabilizer in the second mode. Let the circuit be in the first mode with the switching element 12.1 of main group 3 turned on (Fig. 2, out. 1). . . By the error signal from the threshold element 1, which determines the lower limit of the allowable voltage at the output terminals 10 and 11, the stabilizer switches to the second operating mode, and the control unit 7 performs the following switchings (Fig. 2): time t - control signal supply output 13.N + 1 and the inclusion of the switching element 12.N + 1 auxiliary group f; time t2 Removing the control signal from output 13.1 and turning off the switching element 12.1 of main group 3; time instant t j - feeding the control signal to output 0.2 and switching on the switching element 12.2 of main group 3; time t is the removal of the control signal from output 13.N + 1 and switching off the switching element 12.N + 1 of the auxiliary group C. As a result, switching element 12.1 turns off and switching element 12.2 turns on, the voltage on output pins 10 and 11 rises. Circulating current caused by the closure of one section of the transformer is limited by the ballast resistor 5 and flows at time points (c-1 l) and). The full current of the primary winding flows through the ballast resistor 5 at the time point (,). The value of resistor 5 is determined from the following expressions: di R-Li or 0.5-R-O where is the voltage between adjacent transformer taps; R is the resistance of the ballast resistor; p is the average operating current of the primary winding of the transformer. Formula (2) is used for single-stage voltage regulation in a transient mode, and formula (3) for two-stage voltage regulation. Thus, there are no interruptions in the power supply when switching the windings. The power allocated to the ballast resistor 5 is insignificant, since time (tj-t) is only necessary for reliable switching of the switching elements of the main and auxiliary groups. If the error signal at the output of the threshold element 1 is retained after the first switching, the stabilizer will go to the next position of the switched on switching element 3. which corresponds to an even greater voltage on the load. Subsequently, when the error signal appears at the output of the threshold element 1, the stabilizer will switch until the switching element 12.N of group 3 is turned on. When the error signal appears at the output of the threshold element 1 and the switching element turns on 12.N group 3 at time tj (Fig. 2) will completely relieve the voltage from the load, since the switching element 12.N of group 3 turns off which corresponds to the emergency shutdown of the voltage regulator at the output of the regulated voltage beyond acceptable limits. Consider the case of testing by the stabilizer of the error signal coming from the threshold element 2 (the third mode of operation). Let the switching element .12.3 of group 3 be turned on (Fig. 3, out., 3) When the output voltage increases, for example, due to an increase in network voltage or load reduction, threshold signal 2 is received from the threshold element 2 to the control unit 7 operation mode, and block 7 performs the following switching (Fig. 3): time t - supplying a control signal to output 13.N + 2 and switching on the switching element 12.N + 2 of group 4; time t2- removing the control output signal 13-3 and switching off the switching element that 12.3 of group 3; moment-time feeding the control signal to output 13-2 and switching on the switching element 12.2; time to remove the control signal from output 13.N + 2 and turning off the switching element 12.N + 2 group 4. As a result switching element 12.2 is switched on and switching element 12.3 in group 3 is switched off, the voltage on the load decreases If the error signal at the output of threshold element 2 disappears, the circuit switches to the first operating mode If the error signal remains in the method described for the third mode switches to the switched on state. 12.1 group 3 which corresponds to an additional decrease in the voltage on the load. The difference in the order of the stabilizer switching when the threshold element 1 triggers, caused by a decrease in the regulated voltage below the permissible limit, 6t order of switching at the signal from the threshold element 2, is determined by the need to eliminate an additional decrease in the controlled voltage in the transient mode on the load, because of the voltage drop the ballast resistor 5 when the switching element of the group 4 is turned on at the moment of time (). (Fig. 2 and 3) With the switching element of 12.1 group 3 turned on and the signal appears assoglasovani with threshold element 2 proizo.ydet complete removal of the voltage to the load., as the switching element is turned off 12.1 Group 3), the respective emergency shutdown voltage stabilizer at the output of the regulated voltage within acceptable tolerances. The main and long-term (stationary) mode of operation of the stabilizer is the first mode, while modes 2 and 3 are transitional or non-stationary. As follows from the description of the proposed discrete stabilizer, the connection structure of the primary sections of the transformer is regular, which allows changing the control range over a wide range by simply changing the number of switching elements of the main and auxiliary groups. The use of such a stabilizer involves the creation of a unified series of voltage stabilizers for powering electronic equipment with different power consumption and the required control range by selecting a transformer of the required power and setting the required number of switching elements. The noted technical advantage of the proposed device in comparison with the known one allows to significantly reduce the development time of voltage stabilizers for equipment complexes and reduce their cost for the estimates of using typical units. 9 The use of two groups of switching, elemental and ballast resistors facilitates switching on the main switching elements and eliminates interruptions in power supply when switching branches of a transformer’s sectioned winding ,: Interruptions in power, with discrete tracking of the output voltage, lead to the formation of extracurrents, which destroys the switching elements and reduces their service life. Therefore, the elimination of interruptions in the power supply ensures an increase in the service life of the entire device as a whole, which leads to a decrease in the cost of ensuring the operability of the device, the elimination of power interruptions also leads to an increase in the service life of devices for which the power source is a discrete voltage regulator , since they also exclude the flow of extracurrents. In addition, it improves. output voltage form that. when rectified, the output voltage decreases the ripple. The effectiveness of the proposed device also lies in the fact that the same equipment is used to control the voltage and emergency shutdown of the load when the voltage goes beyond the control limits, determined by the number of main and auxiliary switching elements used in the circuit. This effect simplifies the stabilizer circuit, since it does not require the installation of additional devices for emergency shutdown. The threshold elements and the control unit in the proposed stabilizer circuit are built on chips and discrete threshold elements, which makes it possible to operate the device in a wide temperature range. 10 claims Discrete voltage regulator containing a transformer, the first tap of the primary sectional winding of which is connected to the first input of the stabilizer, switching elements, the first and second threshold elements, characterized in that, in order to extend the range of regulation, to eliminate power interruptions when switching taps and ensuring that the stabilizer g is turned off; when the output voltage to be regulated is outside the set limits, the switching elements are divided into the main group the second input terminal of the stabilizer is connected to the first inputs of the switching elements of the main group and through the ballast resistor to the first inputs of the switching elements of the auxiliary group, the output of the first switching element of the main group is connected to the last tap of the primary winding of the transformer, the output of each of the remaining switches elements of the main group is connected to the output of the corresponding switching element of the auxiliary group and with the corresponding conductive tap of the transformer primary winding across the secondary winding of the transformer and the output terminal of the stabilizer include first and second threshold elements, the outputs of which are connected to inputs entered control unit, each of whose outputs is connected to a control input of the respective switching element. Sources of information taken into account during the examination 1. USSR author's certificate No. 506835, cl. G 05 F l / lt, 1973. 2. USSR author's certificate No. 157977, cl. G 05 F 1/10, 1972. 3. USSR author's certificate No. 532091, cl. .G 05 F I / U, 197t. Fg / g, f fug.