calling all Car and Tractor specialist

[EBK]

Still havent tried your PNP detector Eric. Have you?

I wouldn't bother.  You'll find it is equivalent to the NPN.... 

[Kipper4]

Everything worked out with your detector Eric EXCEPT one thing the IR detector needs the + (anode -Long leg) to Gnd not +9v

So like this

[Kipper4]

However this pans out, whichever IR detector one uses.
It will need to be and external detector sens' pot.
The reason being It reacts completely different in low light and full light.
This could be an issue on stage if there are extremes of light conditions unless light conditions are known before use by the user at the expected time of use.

[EBK]

Everything worked out with your detector Eric EXCEPT one thing the IR detector needs the + (anode -Long leg) to Gnd not +9v

I also had the indicator and vactrol LEDs pointed the other way.  Oh well.

[Kipper4]

Shoot I'll double check my breadboard later.
Thanks Eric.

Ghetto lab demo later maybe.

[EBK]

However this pans out, whichever IR detector one uses.
It will need to be and external detector sens' pot.
The reason being It reacts completely different in low light and full light.
This could be an issue on stage if there are extremes of light conditions unless light conditions are known before use by the user at the expected time of use.

This is why typical circuits modulate the signal before emitting it as IR and demodulate the received light.  Let's you throw out the ambient.

[Kipper4]

I'm sorry I don't understand your last post Eric. Please could you explain further.
Thanks

[EBK]

Here is some additional info (mostly applicable to digital data, but applicable here as well with modification): https://learn.sparkfun.com/tutorials/ir-communication

[Kipper4]

Ok Gottya now thanks for that. In a nutshell the IR transmitter needs to be waggled and the receiver needs to be unwaggled to potentially negate the need for an external pot.

I can't help but feel this would significantly up the cost and size in such a simple idea.
I'm not against the idea of modulation and demodulation.
I guess it might depend also on if a single waggler could be used to do both processes too.

I still have some other potential IR detectors I have not investigated as yet.
I knew there would be pitfall hopefully some highs too.

[EBK]

I like the term "waggler".  As far as extra cost and size, it could possibly be done with a few extra op amps and a small handful of resistors/caps* (maybe. I'd have to look into it more seriously.  Some relatively cheap off the shelf stuff might even do everything for you, but you wouldn't want anything designed to expect, and consequently attempt to "clean up", digital pulses...  ).

*I confess that I mainly build for myself, so I tend to build toward complexity, cost be damned. 

[EBK]

At this point, a lower-tech improvement might be useful.

Try creating a hood for you sensor, a small short tube to block some of the ambient light from the periphery.   

[EBK]

I'll throw this in:
http://electronics.stackexchange.com/questions/24897/how-to-make-ir-proximity-detector-immune-to-the-daylight

[EBK]

I guess it might depend also on if a single waggler could be used to do both processes too.

Almost.  It's essentially the same process each way, but both would need to be done at the same time.  You could reuse the carrier generator part for both, so there is a bit of savings. 

[Ignore this -- purely academic]
If it gets too crazy, you could go all the way sophisticated and use a time-of-flight sensor and a small microcontroller (honestly, that's how I'd do it, but mostly because it appeals to my particular building tastes, so I would find the experience rewarding enough to offset the cost....).  Probably looking at ~$25 USD (~£20 GBP) for the sensor and microcontroller.
[/Ignore this -- purely academic]

[anotherjim]

We've almost been here before...
http://www.diystompboxes.com/smfforum/index.php?topic=29515.0

I can't help thinking if you want simple then...
Use a filter over the sensors. The white-ish plastic window over IR alarm detectors is doing 2 things - focus a wide angle into the sensor AND filter the received radiation to a narrower band of wavelength.

And/or...
As I mentioned earlier, use a differential detector.
https://learn.adafruit.com/pir-passive-infrared-proximity-motion-sensor/how-pirs-work
... honestly, I had nothing to do with the Dragon in the diagram. Actually, there are different versions of the same diagram all over the place with a different beast walking by...

So anyway, there are 2 sensors in the device that are wired in opposite polarity. Like a Figure-8 microphone, they can't see in the middle - everything they receive in common gets cancelled out. But they do see either side of the middle.
It may be possible to arrange things so this is useful.
If reflection from the transmitter will mostly fall on one sensor, then it will be largely immune to ambient that is reaching both sensors.

Add that this gets away from photo-diodes, which can see too much visible light. And don't forget that IR is essentially radiated heat. In the PIR sensor, you could probably just mask over one half of its window with tape or something - the covered sensor will still "see" the ambient heat.

[EBK]

honestly, I had nothing to do with the Dragon in the diagram.

I thought that was a reindeer/duck hybrid.   

[Kipper4]

So its Not like this.
The leds in the diagram ARE as Eric says orientated wrong



Thanks guys
Demo on the way.

btw If you build the tremolo use a non polar charge cap 1uf.

[Kipper4]

https://youtu.be/i5hdmKs6VIo

[anotherjim]

I meant the diagram in the link. See ... I know nobody bothers to follow links, which I why I found the one with deer.

[EBK]

We've almost been here before...
http://www.diystompboxes.com/smfforum/index.php?topic=29515.0

In a different thread, Paul Perry said he used a 555 timer to modulate the transmitter IRED at about 200kHz (in his commercial Spacebeam theramin).  Sounds like a great simple solution to that part of the problem. 

The nice part is (I over thought it before), there is nothing to modulate on the transmitter side.  Just make a square wave with the 555 and you are done.  You can demodulate at the receiver by simply filtering and rectifying.  It turns out that would be cheap and easy after all.   

[duck_arse]

CLR's - noted!

I thought that was a reindeer/duck hybrid.

interesting.

also, I'd have thort the easiest way to make the receiver less ambient sensitive would be to put an IR filter over it, like the one on the front of all those busted remote controls you have.