What value resistor do you have connected between the collector of the LTR and the supply?

We've tried several nothing below 1k but apparently it should be around 22k, I supposed as was mentioned in Post #15, I've made so many mistakes it's incredible.

Both you and DickCappels knew right away something was incorrect in the way I bias or that I connected it in circuit was really wrong.

kv

Edit: Oh, and BTW I think I have so badly damaged it, it works at a low level or is just leaky during operation now that it's in circuit correctly. I'll have to see later what value is in circuit at the moment, later. But I will let you know then and tag you.

 

What value resistor do you have connected between the collector of the LTR and the supply?

Ok, so it's currently connected to a 1k, I decided to connect it to my HeathKit and put it on a 22k but the voltages didn't change between either resistor same .027vdc or thereabout. Time to order a new one and hook it up correctly and put the correct value of resistance on it and re-measure the voltages.

kv

Edit: Plus when I order I'll get 10 just to make sure I have enough.

 

The 5V specification tells the maximum reverse voltage, probably related to the reverse breakdown voltage of the base-emitter junction. Even the detector were installed backwards, it is likely that the resistor would limit the current and that might save the detector in that case.

You are right, I misread the reverse voltage as the forward voltage.

bob

 

Just got over the shipping charge from Mouser 7.99 minimum for snail mail. The thing about this I looked into my order history and I did get 10 of these, simply put I couldn't believe I would order so little with an experimental circuit, usually I have plenty to toy around with so somewhere in my house is 8 more of these little critters, probably on my wife's side of the bed in the darkness that is hell

kv

 

Just got the 4026's today, sure enough it's working now.

12vdc to a 6.8k resistor seems to work best the "On state" with emitter on, emitter of the Dark Phototransistor connected to 12vdc, 6.8k resistor collector to ground rail the voltage drops to .267vdc on both sides of the 4026 then when I shut the IR emitter down or block it, it then increases back to 12vdc therefor blocking. There is a slight voltage of .005vdc

Thanks for spotting my issues.

kv