calling all Car and Tractor specialist

[Kipper4]

Rob
Did you try different couloured leds in yours?

What didnt you like about the 5mm IR Tx &Tr?

I tried the npn but since my IR leds are blown it dint work.
Awaiting a bunch of 10 pair of 5mms in the post hopefully tommorow.
Then I can play some more.

[deadastronaut]

The 5mm are fine,

with the power supply connected rather than a battery
it has a much better tweakable range...

and will likey be ok with just the RX TX...   without the extra RX.

[Kipper4]

I got the 5mm Tx Tr today. They work a treat. Happy days.
Made a few adjustments to the basic detector network. More later.
Back to the breadboard. Meanwhile here's a concept idea.

[Kipper4]

An Infra Tremolo whose depth would be controlled by the detector.
I've yet to trial it and determine further values and check that the lfo waggles.

image removed

change r24 to 47k and the lfo is a good un.

[Kipper4]

R18=6k8
R10=100k

The IR detector and its led Clr as yet untested values to be determined

[EBK]

Rich,
I think something must be wrong with the NPN/PNP diagrams.  You make it look like a PNP is just an upside down NPN....
Should all the diodes be reversed and supply voltages flipped or something similar?

[Kipper4]

I dunno Eric. Maybe someone can confirm this?
I thought thats how I had it wired on the BB. I've been wrong before.

However I've had it working and with the detector as is the led is either on or off.
Although to the ear it seems to fade a bit.
Further work is required but its proof of concept on the breadboard.
I think the R10,R18 needs more work.

[Kipper4]

Image removed

or so I thought.....

[Kipper4]

Your right sir I apologise I'll repost with the corrected npn board.
I can tell you that cost me a few jellybeans and leds to find out.
More ghetto lab reports.

[Kipper4]

Ooops
try this

[Kipper4]

Guys you better strap in and be prepared to leave your fingerprints on the top of some jellybeans.

[EBK]

Your right sir I apologise I'll repost with the corrected npn board.
I can tell you that cost me a few jellybeans and leds to find out.
More ghetto lab reports.

I might just be misunderstanding your circuit....  I'll take another look when my mind is fresh.

[Kipper4]

Above is an amended drawing. Hopefully right this time.

[EBK]

hi rich, heres a nifty lil circuit...

might give this a go myself at some point..


https://www.youtube.com/watch?v=AmkYwvCjXoY

Anyone have a low bandwidth version of this, i.e., a schematic instead of a YouTube video?  So irritating waiting for this to buffer just so this guy can tell me what the next part on his table is. 

[anotherjim]

Sorry Rich, I don't think you switch between NPN & PNP just by swapping the emitter over. The one you show at top for NPN looks right, but can you see the PNP version would have it's base-emitter reversed all the time?
A PNP would act somehow if the emitter is moved to face the indicator LED's, but I'm not sure if that action would be suitable.

[Kipper4]

Thanks guys I think I have it now.
Please tell me if I still got it wrong....

renewed schematic


and for good measure the guy from the youtube vids schematic (screenshot)

[EBK]

This is what I would expect to see as the PNP circuit, assuming your NPN circuit is correct:


Again, I may be misunderstanding your intent.

[Kipper4]

The intent is to provide one IR detector that will go from led dark to light OR
and alternative that will go from led light to dark.

NOT to use both and switch between the two detectors.

I have the you my pnp IR detector on the breadboard now Including the 3k3 and 1K resistors.
Ghetto Lab Report results

In faint evening light it goes : led goes dark to light.

With the window blinds closed : led dark to light same as above.

I'll breadboard yours later Eric.

Now for a test on my NPN from the previous picture post. I'll be back with another Ghetto Lab Report in two ticks.

[Kipper4]

As far as I can tell from the NPN I have on the breadboard now the IR detector diodes are orientated wrong in the last drawing.

ie; + (long leg) of the detector goes to gnd.

Ghetto Lab Report.

Once the above ammendments have been done to the last posted pic

I tried it with
2n5088 tick
2N2222 tick
2n3094 tick
Mpas14 (Darlington) Tick
findings where that a lower gain transistor seemed better response.

I'll post up the corrected drawing.

Still havent tried your PNP detector Eric. Have you?

[Kipper4]

Please note the led CLRs