Logic high/low - Electronic Circuits Projects Diagrams Free

carlson · 14th June 2009, 05:43 AM

How do I use this photo interrupter circuit

Silicon Chip Online - Circuit Notebook

at 3 volt (without relay) to pull pins 12/13 (in12/22) of this IC

BA6845FS Datasheet pdf - Magnetic Disk LSIs > FDD stepping motor driver - ROHM

low when beam blocked and high when beam not blocked.

MikeMl · 14th June 2009, 06:22 AM

I'd wire it as in the train detector, but put a second inverter after the first. That would give you the high.

If you can move the load resistor to the collector of the photo-transistor, then you can do it with only one Schmitt inverter.

carlson · 14th June 2009, 06:35 AM

Can I do it without the invertor

MikeMl · 14th June 2009, 06:51 AM

Probably not, because the transition from on/off off/on will be not be a clean logic transition, will be too slow, and because of the low-gain optointerupter, will float around near the trip-point being modulated by 120Hz incident light.

carlson · 14th June 2009, 07:02 AM

terrific ta thanks

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14th June 2009, 05:43 AM	#1
carlson	Logic high/low How do I use this photo interrupter circuit Silicon Chip Online - Circuit Notebook at 3 volt (without relay) to pull pins 12/13 (in12/22) of this IC BA6845FS Datasheet pdf - Magnetic Disk LSIs > FDD stepping motor driver - ROHM low when beam blocked and high when beam not blocked.

14th June 2009, 06:22 AM	#2
MikeMl	I'd wire it as in the train detector, but put a second inverter after the first. That would give you the high. If you can move the load resistor to the collector of the photo-transistor, then you can do it with only one Schmitt inverter.

14th June 2009, 06:35 AM	#3
carlson	Can I do it without the invertor

14th June 2009, 06:51 AM	#4
MikeMl	Probably not, because the transition from on/off off/on will be not be a clean logic transition, will be too slow, and because of the low-gain optointerupter, will float around near the trip-point being modulated by 120Hz incident light.