SU1483497A1 - Demagnetization device - Google Patents

Abstract

The invention relates to electrical engineering, more specifically to devices for demagnetization of parts on magnetic plates of grinding machines. The purpose of the invention is to increase speed, increase the reliability and quality of demagnetization. The device contains a series-connected alternating voltage source, a step-down transformer 1, a thyristor converter 2, an inverter 3 and an electromagnetic plate 4, as well as a control unit 5. One output of the control unit is connected to the thyristor converter and the other to an inverter 3. The inverter 3 is made thyristor , moreover, the inverter 3 and the Converter 2 is made in the form of a single-phase bridge circuit. The control unit 5 includes a voltage-frequency converter 6, two counting flip-flops 7 and 8 integrating RC = chain 9,10 and a source of constant voltage 11, and the input of voltage-frequency converter 6 is connected via integrating RC = chain 9, 10 with a constant voltage source 11, and the output through two series-connected counting trigger 7.8-with a thyristor converter 2 and an inverter 3. 2 Il.

Description

The invention relates to electrical engineering, in particular, to devices for demagnetizing ferromagnetic parts on magnetic plates of grinding machines.

The purpose of the invention is to increase speed, increase the reliability and quality of demagnetization.

Fig. 1 is a circuit diagram of a device for demagnetization; Fig. 2 shows time diagrams of voltages.

The device contains a source of pulsing of pulses, respectively, 2 and 4 times ps relative to the input frequency, while the counting trigger 7 controls the thyristor converter 2 and reduces the pause between the control pulses simultaneously with a decrease in their duration, and the counting trigger 8 controls A triac inverter 3 and provides a change in the polarity of the demagnetizing voltage on the plate. Due to the fact that both the first 7 and second 8 counting triggers are connected to the last voltage, which reduces the transient, their work is strictly synchronized

3497

pulses, respectively, 2 and 4 times ps relative to the input frequency, while the counting trigger 7 controls the thyristor converter 2 and reduces the pause between the control pulses simultaneously with a decrease in their duration, and the counting trigger 8 controls the ty the inverter 3 and provides a change in the polarity of the demagnetizing voltage on the plate. Thanks to the fact that both the first 7 and second 8 counting triggers are connected

formator 1, thyristor converter 2, thyristor inverter 3, electromagnetic plate 4, control unit 5, which includes voltage-frequency converter 6, 20 two consecutively connected counting triggers 7.8, integrating RC-chain 9,10 and source 11 constant voltage. A step-down transformer 1 is connected to a thyristor inverter 3 via a thyristor converter 2, made according to a single-phase bridge circuit. The control of the thyristor converter and the thyristor inverter is performed by the control unit 5.

The device works as follows.

The electromagnetic plate 4 is supplied with opposite-polarity pulses of constant amplitude and a smoothly decreasing duration and pause between them. When this happens, the plate itself and the details on it are demagnetized. .40

A reduction in the duration of the demagnetizing voltage packets and the pauses between the packets is carried out by the control unit 5. Source 11 constant voltage does not integrate 45: rudder RC-chain 9,10, which forms a voltage across the converter 6 input - frequency is a single sawtooth voltage pulse, the duration of which determines the time 50 demagnetization. As a result of the impact of this sawtooth voltage pulse, at the output of the converter 6, a packet of unipolar pulses is formed, the follow-up period of which 55 smoothly decreases. With transform-. 6 pulses are fed to sequentially connected counting triggers 7 and 8, which reduce the tracking frequency, so the switchboard is made only at the moment of its complete de-energization, which eliminates switching overvoltages on the windings of the plate and simplifies the thyristor inverter circuit.

The use of a device for demagnetization of ferromagnetic parts on magnetic plates of grinding machines will make it possible to increase labor productivity, ease working conditions, increase reliability and efficiency of demagnetization.

Claims (1)

Invention Formula A demagnetizing device containing a series-connected alternating voltage source, a step-down transformer, a thyristor converter, an inverter and an electromagnetic plate, as well as a control unit, one output of which is connected to the thyristor converter, and the other to an inverter, speed, increase the reliability and quality of demagnetization, the inverter is made thyristor, and the inverter and the converter are made in the form of a single-phase bridge circuit, the control unit includes a voltage converter. - frequency, two counting flip-flops, integrating an RC-chain and a source of constant voltage, the input of the converter-voltage - the frequency is connected through an integrating RC-chain to a constant voltage source, and the output through two successively included counting triggers - with thyristor converter and inverter. ABOUT U7 about Slips FIG. 2 alone t