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Incrementing Positioning Control Circuit

IP.com Disclosure Number: IPCOM000098999D
Original Publication Date: 1964-Mar-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 3 page(s) / 57K

Publishing Venue

IBM

Related People

Scalone, JM: AUTHOR [+2]

Abstract

Accurate positioning of a member moved by response devices, such as electrical clutches, is obtained by a circuit supplying short incrementing pulses during the approach to final position.

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Incrementing Positioning Control Circuit

Accurate positioning of a member moved by response devices, such as electrical clutches, is obtained by a circuit supplying short incrementing pulses during the approach to final position.

Document transport belt 1, mounted for rotation by opposite rotatable clutches 2 and 3, bears sets of reflective areas 4, 5 and 6 at fixed locations. The reflective areas are illuminated by a light source and are sensed by respective photocells 7, 8 and 9 which apply signals to respective amplifiers 10, 11 and 12.

A forward or reverse drive signal, indicating the direction of motion desired, conditions pairs of And's 13, 15 or 14, 16. These And's are each further conditioned by the output signal from inverter 17 which is supplied by the signal from amplifier 11 supplied by photocell 8 sensing home position mark 5. And's 13 and 14 are conditioned by the signal from amplifier 10 supplied by photocell 7 sensing mark 4. And's 15 and 16 are supplied by the signal from amplifier 12 supplied by photocell 9 sensing mark 6.

At the conclusion of the coarse forward or reverse motion, which is one actuation of the clutches, an increment gate signal is provided for a fixed time to turn on oscillator 18 and condition And's 19 and 20. The output of oscillator 18 turns on single-shot 21 whose output is supplied to And's 22 and 23 providing a timed acceleration signal to them. The output from single-shot 21 is also supplied to inverter 24 which turns on single-shot 25 when single-shot 21 times out to provide a short braking signal to And's 26 and 27. The duration of the two successive single-shot signals is approximately equal to the pulse duration of oscillator 18.

An example of circuit operation is as follows. Assuming the desired coarse movement is forward, And's 13 and 15 are conditioned. At the conclusion of the coarse movement, the increment gate signal appears to condition And's 19 and 20 and turn on oscillator 18. If member 1 has moved an insufficient amount, photocell 7 produces a signal from light reflected by strip 4. No signal occurs from photo-cell 8, since home strip 5 is not positioned under it. As a resu...