SU756391A1 - Stabilized dc voltage source with several outputs - Google Patents

Description

The invention relates to radio engineering, in particular to the power sources of radio equipment.

A stabilized source of several constant voltages is known, 5 containing a series-connected supply generator and a stabilized constant-voltage converter to constant voltage, the transformer of which is made with several 10 secondary windings, each of which is connected to a rectifier with a filter connected to the corresponding output of the source, one of which is connected with a control input of a fixed 15 V DC voltage converter 3, constant Ϊ.1].

In known sources, when providing multiple output sources 20, variations in the load currents of some sources over a wide range affect others due to changes in the magnetic losses in the core and losses in the copper of the output transformer. The use of special winding does not sufficiently increase the accuracy of stabilization, the output voltages. This is especially true for low-power converters.

2

The closest to the proposed technical solution is a stabilized dc voltage source with several outputs, containing a series-connected supply generator and a stabilized dc-to-dc converter, the transformer of which is made with several secondary windings, to which the rectifier with a filter connected to corresponding source flow and with the corresponding input of the averaging block, the output connected to the control input of the station ilizirovannogo inverter DC to DC [2]

The disadvantage of this source is the occurrence of overvoltages on individual outputs during switching on. Indeed, assuming that capacitive filters are capacitive and that their time constants are unequal to each other, which is quite likely in the case of different load currents and different ripple requirements for individual output sources, it can be argued that the delay in establishing a feedback signal relative to establishing a nominal voltage is possible

756391

on separate output sources. And then until the establishment of the feedback signal from these sources there will be overvoltages. Moreover, overvoltages occur to a large extent at the outputs with the lowest filter time constant.

The aim of the invention is the exception. overvoltage on individual outputs during power up.

This is achieved by the fact that in a stabilized DC voltage source with several outputs containing a series-connected supply generator and a stabilized DC / DC converter, a transformer which is made with several secondary windings, each of which is connected to a rectifier with a filter, connected to the corresponding from the source outputs and the corresponding input of the averaging unit, between one of the source outputs and the output of the averaging unit, in series There are a voltage divider and a switch of two oppositely connected diodes, the output of which is connected to the control input of a stabilized DC / DC converter.

The drawing shows a block diagram of a stabilized source of several constant voltages.

The source contains a power generator 1, a stabilized DC / DC converter 2, the inverter transformer 3 of which is made with several secondary windings, each of which is connected to rectifiers with filters 4, 5 and b, connected to the corresponding outputs of the source and with the corresponding input block 7 averaging. Between the output of the filter 6 and the output of the averaging unit 7, the voltage divider 8 is connected in series and the switch 9 of two oppositely connected diodes 10 and 11. The middle point of the diodes 10 and 11 is connected to the control input of the constant-to-constant converter 2.

The rectifiers 4, 5 and 6 connected in series, the averaging block 7 and the diode 11 form a feedback circuit. The presence of this connection allows you to control the inverter 2 DC voltage in accordance with the error signals that occur with changes in both the supply voltage and the loads in the output voltage sources.

The device works as follows.

At the moment of switching on the power generator 1 at the outputs of rectifiers with filters 4, 5 and 6 (and therefore at the output of averaging unit 7) the voltages are zero. With a zero control signal, in the case of using latitudes, but pulse modulation, in the stabilized converter 2 the pulse duty cycle will be minimal, and in the case of using continuous regulation, the regulating element will be fully open. Thus, at the moment of switching on, the capacitors of the power supply filters 4.5 and 6 will be quickly charged. After some time, the output of the filter 5 is set to a nominal positive voltage, since the filter 6 is selected with a minimum time constant at rated load. Further, this voltage is divided by divider 8 to a value slightly lower than the nominal output voltage from averaging unit 7, and through the forward connected diode 10 is fed to the control input of the stabilized converter, that is, the feedback only works from the output source that is most quickly established by voltage. Upon reaching the rated output voltages at the outputs of the rectifiers with filters 4 and 5, the output control of the averaging unit 7 will establish the nominal control voltage. The diode 10 is closed and the feedback acts only through averaging unit 7 from all output sources, ensuring their stabilization.

The use of a feedback target switch eliminates overvoltages that occur during the transient process of establishing nominal voltages at the output sources, which increases the reliability of devices using this stabilized source of several constant voltages.

Claims (2)

Claim A stabilized dc voltage source with several outputs, containing a series-connected supply generator and a stabilized dc-to-dc converter, whose transformer is made with several secondary windings, each of which is connected to a rectifier with a filter connected to the corresponding output and the corresponding input of the averaging unit, characterized in that, in order to increase reliability by eliminating overvoltages on individual outputs during switching on , between one of the outputs and the output of the averaging block, the input voltage divider and the switch of two counter-switched diodes are connected in series, the output of which is connected to the control unit 5 756391 6 th input stabilized dc voltage converter in permanent. Source! .- information taken into account in the examination 1. Romash E.M. Transistor converters in electronic equipment power supply devices. M., "Energy", 1975, p. 109, fig. 3-2. 2. USSR author's certificate ₅ No. 551629, cl. C 05 P 1/64, 1975.