Browse Prior Art Database

Solenoid Turn-on/turn-off Detector

IP.com Disclosure Number: IPCOM000060121D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Turner, JF: AUTHOR

Abstract

A circuit is described which detects whether a solenoid operates a full stroke when energized by detecting the "notch" that occurs when the solenoid picks or drops.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Solenoid Turn-on/turn-off Detector

A circuit is described which detects whether a solenoid operates a full stroke when energized by detecting the "notch" that occurs when the solenoid picks or drops.

The circuit functions to couple the solenoid current waveform into a circuit which separates the "notch" with a high filter and makes a comparison with the solenoid turn-on logic signals.

The specific embodiment of the circuit utilizes a small series resistor 1 to monitor current through the solenoid coil 2. The current wave is coupled through amplifier 3 to high pass filter 4 to select the "notch". The "notch" signal is fed through amplifier 5 to a shaping circuit 6. The output of shaping circuit 6 is a pulse which corresponds in time with the "notch" generated when the solenoid picks or drops. The pulse is coupled to the count down input of up-down counter
7. A signal corresponding to the solenoid turn-on logic signal is coupled to the count up input of counter 7. This operation results in the counter being counted up one count for each logic signal. If there is a corresponding "notch" signal, the counter is counted down one count. The output of counter 7 is sampled at a selected time after a turn-on signal, and a count of zero indicates normal operation while a non-zero count indicates an error condition.

Disclosed anonymously.

1