SU1610564A1 - Voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in secondary power supply and electric drive systems. The mains rectifier 1 is connected to the input of the inverter 3, shunted by capacitive filter 2, through the power switch 4, shunted by the starting resistor 5. The power switch 4 is controlled by the control unit 6, the input of which is connected to the output of the NAND 9 logic element. A zero at the output of the logical node IS-NE 9 appears when the signals at the output of the zero voltage detector 7 and the one-shot 8 are present at the same time. This closes the power switch 4 and shorts the starting resistor 5, which limits the starting current. 2 Il.

Description

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The invention relates to electrical engineering and can be used in the systems of secondary power supply and electric drive ;.

The purpose of the invention is to increase reliability by reducing the starting current of

Figo 1 shows the block diagram of the proposed Converter; Figure 2 shows diagrams explaining the principle of its action.

The converter contains a mains plug 1 connected to a capacitive filter 2 and an inverter 3 via a power switch 4, in parallel with which a starting resistor 5 and a control node 6, a zero voltage detector 7 and a single vibrator 8 o are connected. AND-NOT 9, the input of which is connected to the output of the detector 7, and the output - to the input of the unit 6 of the control

Voltage converter operation em as follows

When the circuit is connected to the primary source, the voltage of the one-shot 8 vibrates the signal of the logical zero CHz, the voltage (Fig2V), stops the power switch 44. At the same time, the capacitors of capacitive F1H1tra 2 are charged through the starting resistor 5 (FIG. 2a). and the zero-voltage detector 7 detects the I1 | pulses of positive polarity, which form at moments of) when the voltage on the power Kjjno4e is zero (fig2b) at the time point when there is a T & amp on both inputs. AND-NOT 9 there are signals of a logical unit, at its output a logical zero signal is generated, which acts on the control of the input of the node 6 o Power switch 4 at. This closure is maintained and held open by a signal acting on the additional inverter input. When the voltage on the output of the rectifier 1 (FGS 2a) and becomes equal to the voltage U, to which the capacitors of the capacitive filter 2, charged,. through the power switch 4 a current flows (FIG 2d), determined by the rate of voltage change. For example, if the capacitors of the capacitive filter 2 were charged before the voltage, 95Ugy ,, by the time the sieve key 4 was turned on, then the starting current through the power switch 4 would be 3 times less than in the prototype device. The amplitude of the starting current i depends on the duration of the one-shot pulse, its timing time is determined by parameters and can be limited to almost any desired level

Claims (1)

Invention Formula A voltage converter containing a mains voltage, the output of which is connected via a power switch to the inverter input, bypassing a capacitive filter, and a zero voltage detector connected in parallel with the power switch, and an output connected to the control circuit of the power switch, characterized in that the purpose of nosbmie reliability is by reducing the starting current, a shunt power switch is introduced, a starting resistor, a one-shot connected via the power supply circuit parallel to the power switch, and the AND – NE logic element the first input of which is connected to the one-shot output, the second input to the output of the zero voltage detector, and the output to the input of the control unit, and the control circuit of the silo key is additionally connected to the output of the inverter. FIG. 2