Sharp GP1A73AJ000F photointerrupter

Other Hardware Sensors
1

Morning gang...

I've salvaged one of these from an old copier, but it doesn't seem to work. Output is meant to be high when the light is interrupted, but when I put 5v on Vcc pin 1 and Ground pin 3, I get nothing out of Vout pin2 and ground with the light interrupted or not.

Reading the data sheet http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp1a73a_e.pdf, I see that Vout should be up to 90% of Vcc with RL = 47k. Does that mean this is some kind of switching device (like a PC power supply which only produces voltage under load), and that I should put a 47k load into play?

If it does need a load, just for testing purposes where would that go: Vout to Ground?

TIA,

Jim

(on the other hand, of course the sensor may be broken....)

2

It probably just needs a pull-up resistor (output to Vcc resistor). That way it's on Vcc with an inactive sensor and pulled to ground when the sensors get's active. Many sensors are connected this way.

3

Thanks Pylon... yes I subsequently found some other schematics that pointed out the need for the pull-up. Still no joy though.

But never mind, it's no biggy, it was a harvested part and I was just fiddling around. I'll check out my local supplier and buy a few new ones and wire them properly from the start.

Jim