SU796929A1 - Device for automatic demagnetizing permanent magnets up to predetermined value of magnetization - Google Patents

Description

(54) DEVICE FOR AUTOMATIC DEMAGNETIZATION OF PERMANENT MAGNETS TO THE SPECIFIC VALUE OF MAGNETICITY

go seeker. In addition, a device with a memory unit on a stepper finder has low reliability and a short service life of the device.

The purpose of the invention is to reduce the demagnetization time and increase the reliability of the device.

The goal is achieved in that the device’s memory unit contains a source of pulse voltage, a key, two n-bit trigger counters with setting and counting inputs, and two key converters of a binary code into a voltage, one of which has a separate input for closing all keys. The counting inputs of the trigger counters are connected via a key, commued by the control unit, to a source of pulsed voltage. Outputs trigger counters are connected to the gate electrodes converters keys binary to voltage inputs preobrazvateley binary code in the voltage connected to the source of the offset voltage compensating meter magnetization outputs preobrazvateley binary code in voltage across summirutatsy transformer are connected to an adder reference signals, adjusting trigger counter inputs and individual closing inputs of all keys of the binary-to-voltage converter are connected to a block to control.

FIG. 1 shows a block diagram of the device; in fig. 2 - functional diagram, control unit; in fig. 3 - the same, the memory block; in fig. 4 - dependence of the magnetization of the magnet on the demagnetizing field.

The automatic demagnetization device (see Fig. 1) consists of an electromagnet 1, in the working gap of which a demagnetized magnet of the controlled electromagnet power supply 2, the control unit 3, the magnetization compensation meter 4, the adder 5 of the reference signals and the memory unit 6 are placed. The control unit 3 (see Fig. 2) consists of Schmidt trigger 7, trigger 8 with separate inputs, trigger 9 with counting and separate inputs, and a AND 10 coincidence circuit.

The magnetization compensation meter 4 is made according to the usual compensation meter circuit and consists of a magnetization sensor, a reference signal block, a comparison circuit, a differential signal amplifier and a phase detector. In contrast to the conventional circuit, the signal from the reference signal block is fed to the comparison circuit directly, and after summing it up with the voltage from the memory block in the reference signal adder.

The memory block b (Fig. 3) consists of two n-bit trigger counters that control the operation of binary-to-voltage converters (consisting of dividers on resistors and key stages, for example, on field-effect transistors), a source 11 of pulsed voltage , a key 1.2 and a summing transformer 13. With the open key 12 and no locking voltages at points 14-16, the pulses from the source 11 of the pulse voltage are read out by trigger meters that switch the binary code converters to voltage which has the frequency of the reference signal (due to the powering of the transducers from the generator of the reference voltage of the compensation magnetization meter 4). As a result, the voltage at the output of the binary-to-voltage converters turns out to be proportional to the number of pulse counters received at the input, i.e. with the continuous supply of voltage pulses on the windings of the summing transformer 13 linearly increases. When closing key 12, the flip-flops retain state corresponding to the calculated number of pulses. Triggers can be set to their initial state by applying the potential to points 14 and 15. In this case, the output voltage of the converters is zero. The output voltage of the transducers can be set to zero, also in an arbitrary state of the counting triggers, by applying the locking potential key to point 16.

The device works as follows.

Claims (1)

1. USSR author's certificate 15 No. 511636, cl. H 01 F 13/00, 1976.