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# Regulation of a Magnets Force

IP.com Disclosure Number: IPCOM000082179D
Original Publication Date: 1974-Oct-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 47K

IBM

## Related People

Dobson, DR: AUTHOR [+2]

## Abstract

The efficiency of series regulators is very low; therefore, these regulators generate considerable heat. With this method the efficiency is much higher, and, as a result, the heat and power supply are reduced.

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Regulation of a Magnets Force

The efficiency of series regulators is very low; therefore, these regulators generate considerable heat. With this method the efficiency is much higher, and, as a result, the heat and power supply are reduced.

Most systems regulate the applied voltage; then the average current and force are proportional to the coil's resistance. Coil materials have a large temperature coefficient, which increases both the power used by the magnet and the power used in the regulator. This system uses an unregulated supply voltage. The integral of the chopped applied voltage is monitored; therefore, the average current is a function of the coil's resistance and inductance. The inductance is not a function of temperature.

The basic block diagram is given in Fig. 1. To operate one magnet, the control logic 10 turns on the appropriate magnet driver 12, the switch 14, the integral function 16 and the timer 18. When the integral function 16 has been satisfied, it sends a pulse to the control logic 10 that turns off the switch 14 and the current is allowed to decay through the suppression diode 20.

The timer 18 will then time out and send a pulse to the control logic 10 that will then reactivate the switch 14, the integral function 16 and the timer 18. This cycle is repeated at a rate faster than the magnet's time constant. When a magnet is turned off the control logic 10 turns off only that magnet driver 12, but continues the cycle for any other magnets.

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