SU501456A1 - Stabilized transistor converter - Google Patents

Description

one

The invention relates to the field of power electrical engineering and can be used in the development of secondary power sources.

The stabilized transistor converters are known, which contain a power supply unit and connected to it via an adjusting transistor switch and an input choke, an inverting stage with a transformer, a series of windings of which are connected to capacitors bypassing capacitors through appropriate rectifiers.

In known converters, a zener diode with a reference voltage greater than the nominal voltage across the primary winding of the specified transformer and a lower breakdown voltage of the inverting cascade is connected parallel to the input of the inverting cascade. The presence of such a Zener diode protects the transistors from switching overvoltage peaks. However, with ET01M in a Blitron, some power is dissipated (in the order of 3-5% of the converted power), which leads to a decrease in efficiency. converter.

The proposed converter is characterized in that in it a parallel diode is connected in parallel with a string formed by interconnected regulating tracking key and input choke.

This provides an increase in the lb. devices while simultaneously protecting the inverting cascade transistors from switching overvoltage peaks.

The drawing shows the scheme of the proposed converter, where 1 is the power supply unit; 2 - AC network; 3 - regulating transistor switch; 4 - input choke; 5i-54 - winding transformer inverting cascade; 6 - inverting cascade; 7.8, 9 - output rectifiers; 10, 11, 12 - capacitor filters; 13-15 - converter load; 16 - master oscillator; 17 — voltage source; - transformer winding master oscillator; 19 is a comparison unit; 20 - pulse-width modulator; 21 control node; 22 - switching transistor; 23i-23z - control transformer windings; 24 - shunt diode; 25-28 - inverting cascade transistors; 29 - diode.

The scheme works as follows. In a steady state, the energy from power supply 1, formed, for example, by a non-alternating current network 2 with a corresponding rectifier and a capacitor filter, is transmitted through control transistor switch 3 and input choke 4 to inverter circuit 6i primary winding 5i and further from secondary windings 52 -04 of this transformer through output rectifiers 7, 8, and 9 with capacitor filters 10, 11, and 12 to the corresponding loads of 13, 14, and 15 of the converter.

The master oscillator 16, connected to the voltage source 17, forms on the primary 18i and secondary 182-18 transformer windings temporary rectangular paps with a coefficient of 0.5 pulse filling. The misalignment grid is between the voltage on the load 15 and some reference voltage of the comparison block 19 from the output of this block enters the input of the pulse width modulator 20, which is synchronized in frequency with the winding 18b of the trapsformer of the master oscillator. The output pulses of the modulator, the duration of which is determined by the error signal at the output of the comparator unit 19, are fed to the input of the control unit 21 containing the switching traffic 1store 22n the control transformer with the primary 23 | n secondary 232 and 23z windings. When the voltage of the network 2 and, respectively, the voltage at the output of the power supply unit 1, as well as the values of the loads 13, 14 of the NLP 15, change the pulse filling factor on the windings 23i-23z of the transformer, which leads to a change in the ratio of the duration of the closed and open states of the regulating switch 3 and, as a result, to voltage stabilization at all loads 13, 14 and 15. Shunt diode 24 normally eliminates breaking of the circuit of the throttle 4 when the control switch is opened.

Since the nominal voltage on the primary winding 5) of the transformer is always less than the output voltage of the power supply unit 1, if using the ideal transformer and transistors 25-28 of the inverting stage, the installation of the diode 29 would not be required. However, the presence in the real transformer of inductances of the scattering and inter-turn e xyoi, and in real transistors inertial effects (including the effect of dissipation of excess charge

base) causes, immediately after the change of polarity of the voltage on the windings 18i-187 of the transformer, the cessation of current flow through the transistors 25-28 of the inverting cascade for a period of 3 to 10 percent of the half period of these voltages. At the same time, the T01K throttle closes on the zeppe: choke 4 - diode 29 - capacitor filter of the niti unit 1 - shunt diode 24 - choke 4 (the transistors of the regulating switch 3 do not conduct at the current interval in question), which ensures the recovery of the energy of the chokes in this power supply unit and voltage limiting in transistors 25-28 at the level corresponding to the output voltage of the litany unit.

In practical use schemes there is no need for a source of 17

voltages to apply an external source, since the presence of stabilized rectangular voltages on the windings 5i-5 of the transformer allows using the additional winding of this transformer and co-voltage rectifier and capacitor to form a source of stabilized constant voltage.

As a master oscillator 16, pulse width modulator 20 and block 19

In comparison, any of the known schemes may be used.

Claims (1)

Invention Formula A stabilized transistor converter containing a power supply and connected to it via a control switch 1 and an input choke inverting cascade with a transformer, the series of windings of which is connected to shunt capacitors to loads through an appropriate capacitor, in order to increase the voltage. d., parallel to the chain formed by interconnected regulating transistor switch and input choke, included diode. yy  R (5Z 3 7 P GP Ij