Browse Prior Art Database

Control of Pulse Width and Amplitude

IP.com Disclosure Number: IPCOM000076769D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Barcomb, JG: AUTHOR

Abstract

As shown in Fig. 1, a capacitor C is connected through a resistor R1 to a DC source for charging, and is discharged through a coil L by a transistor T. By adjusting R1 any value of hold current can be obtained. Diode D prevents spikes.

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Control of Pulse Width and Amplitude

As shown in Fig. 1, a capacitor C is connected through a resistor R1 to a DC source for charging, and is discharged through a coil L by a transistor T. By adjusting R1 any value of hold current can be obtained. Diode D prevents spikes.

If R1 is replaced by a diode D2, as shown in Fig. 2, the source can be AC. The capacitor can charge on the positive half-cycle and the circuit can be fired on the negative half. A reset to the transistor can be obtained from the AC source. If a silicon-controlled rectifier SCR is used as shown, it will automatically reset.

If this circuit is used to drive coils, such as hammer drivers, and the duty cycle is low enough, resistor R1 can be made large enough so that if a fault occurs, no coil damage will occur. This has always been a problem with high- energy pulse coils.

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