SU1598078A1 - D.c. to d.c. voltage converter - Google Patents

Abstract

This invention relates to electrical engineering and can be used in secondary power supply sources. The goal is to expand the scope by increasing the stability of the output voltage. The device contains a transformer 1, a rectifier 2, transistors 4, 5, a rectangular voltage generator 6 and a threshold element 7, a diode 9, a choke 8 and a capacitor 3. When the converter operates, the threshold element 7 produces a high and low voltage level depending on output voltage values. In this case, the generator 6 is turned off or turned on and allows current to flow from the input voltage source to the output through the transistors 4.5 and through the rectifier 2, maintaining the output voltage within the specified limits. 2 hp f-ly, 3 ill.

Description

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The invention relates to electrical engineering and can be used in the sources of secondary power supply systems of radio engineering, automation and computer technology.

The purpose of the invention is to expand the field of application of a DC converter by increasing the stability of the output voltage.

Figure 1 shows the electrical circuit of the DC / DC converter; Fig. 2 is a diagram of a threshold element and a rectangular voltage generator; FIG. 3 shows the diagrams of currents and voltages on the converter elements.

The DC converter - to DC - contains an output transformer 1, the secondary winding of which is connected via rectifier 2 to capacitor 3, the extreme terminals of the primary winding of transformer 1 are connected to the first power terminals of transistors 4 and 5, the control inputs of which are connected through a square generator voltage and threshold element 7 with output terminals, choke 8 and diode 9. The rectangular voltage generator is made, for example, according to the scheme of a two-stroke transformer generator with a positive reverse However, the base-emitter junctions of transistors 10 and 11 are shunted by additional transistors 12 and 13, the control of which inputs are connected to the output of threshold element 7, made, for example, according to the Schmidt trigger circuit.

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When DC input and supply voltage is applied to the square voltage generator 6, transistors 4 and 5 begin to switch. The secondary voltage of the transformer 1 is then rectified by rectifier 2 and supplied to the load. Due to the inertia of transistors 4 and 5, at the moment of their switching, a mode of simultaneous open state of both transistors CTODOB 4 and 5 occurs. The primary winding of transformer 1 becomes short-circuited. In the circuit, the first input terminal is the primary winding of the transformer 1 — transistors 4 and 5 — choke 8 — Kon, censor 3 — the second input output begins to flow through the current, which linearly increases in time and is inversely proportional to the value of the inductance of droplets 8. the current of the transistors 4 and 5 is closed through the choke 8 and the load.

After the voltage 14 at the output terminals exceeds the upper limit (Fig. 3), the threshold element 7 is activated, the incoming voltage 15 of which (Fig. 3) through the control input affects the rectangular voltage generator 6. At the same time, additional transistors 12 and 13 of the square-voltage generator are opened, shunting the base-to-junction transition of the transistors 10 and 11 of the generator 6, locking them. Generation stops (15, fig. 3). Transistors 4 and 5 are closed. The current in the load circuit is maintained by the energy stored in the capacitor 3 and in the inductor 5-8, the current of which is closed through the diode 9. After the voltage 14 decreases at the load below the lower limit (Fig. 3), the threshold element 7 returns to its original state. The rectangular voltage generator 6 0 is switched on again (16, FIG. 3), and then the processes are repeated. The accuracy of voltage stabilization at the output terminals is determined by the sensitivity zone of the threshold element 7, 5 can be obtained sufficiently high (1-2%) and is limited only by the drift of the source of the reference voltage.

The proposed constant-to-constant voltage converter allows 0 to obtain a more stable output voltage while maintaining the positive properties of the known (reduced operating voltage on the switching elements), as well as to have a higher 5 efficiency due to the elimination of through-currents. In addition, the elimination of cross-cuttings reduces the level of input current spikes, which improves the weight and size characteristics.

Claims (2)

Claim 01. A DC / DC converter containing an output transformer, the secondary winding of which is connected via a rectifier to a capacitor connected to the output 45 terminals, the middle terminal of the primary winding of the output transformer is connected to the first input terminal, and the extreme terminals are connected to the first power outputs of the transistors, the second power outputs 50 of which are combined and connected to the first output of the drossel, a diode, the first output of which is connected to the second input and the first An output terminal, characterized in that, in order to expand the application area 55 by increasing the output voltage stability, a rectangular voltage generator and a threshold element are inputted, the input of which is connected to the output terminals, and the output is connected through a rectangular generator the voltage from the control inputs of the transistors, the second power outputs of which are connected to the second output of the diode and through the said choke to the second output output. 2. The converter according to claim 1, of which is a rectangular voltage generator, which is made according to the scheme of a two-stroke transformer generator 0 positive feedback, the base-emitter transitions of the transistors of which are shunted by additional transistors, the control inputs of which are connected to the output of the threshold signal. 3, the Converter according to claim 1, of which is a threshold with the fact that the threshold element is made according to the Schmidt trigger scheme. .J 2 14 Fig.Z