question about LED's for clipping device

[plexi12000]

hi dudes.... i want to build a tube screamer and use LED's.  tayda has non-light emitting diodes. 3mm, 5mm and 10mm.

i'm assuming these are the ones to use for clipping?  can i use any size?  thank you!

[mcknib]

Bog standard LED's will do the job most folks use 5mm but you can use 3mm too, clipping obviously depends on the fwd voltage when they start to conduct different colours will give you different fwd voltages:




Although I've got to say I don't notice a whole hellava lot of difference anyway just FYI

[amptramp]

Keep the LED's in the dark when you use them as clipping diodes because ambient light increases the leakage current to the point where they can be used as photodiodes.  You don't want stage lighting changing the characteristics or injecting hum.  Some people have run afoul of this when they tried to mount the clipping LED's on the outside to show how much clipping they were getting.

[plexi12000]

Bog standard LED's will do the job most folks use 5mm but you can use 3mm too, clipping obviously depends on the fwd voltage when they start to conduct different colours will give you different fwd voltages:




Although I've got to say I don't notice a whole hellava lot of difference anyway just FYI

thanks for responding-  what are "bog" standard LED's?

[bluebunny]

I think this was a counter-reference to "non-light emitting diodes", whatever they are...   

[duck_arse]

"bog standard" are very muck alike "garden variety".

what does a non-light emitting light emitting diode look like (or can't we see it?).

literally anything tayda sells will be "bog" standard.

[ElectricDruid]

what does a non-light emitting light emitting diode look like (or can't we see it?).

IR diodes? I've got a few that I took out of dead TV remotes and such like. Never thought of trying them as clipping diodes though.

Tom

[mcknib]

Sorry just means normal LED's I'm forgetting this is an international forum

[amptramp]

what does a non-light emitting light emitting diode look like (or can't we see it?).

IR diodes? I've got a few that I took out of dead TV remotes and such like. Never thought of trying them as clipping diodes though.

Tom

IR LED's have a lower forward voltage than visible LED's.  They may be as low as 1.1 volts which will suit some purposes - a bit higher than silicon but lower than red LED's.

[plexi12000]

Sorry just means normal LED's I'm forgetting this is an international forum

no prob buddy-- thanks for responding.  and thanks for posting the chart!!

[mth5044]

Sorry just means normal LED's I'm forgetting this is an international forum

no prob buddy-- thanks for responding.  and thanks for posting the chart!!

But wait, what are the 3mm, 5mm and 10mm non-light emitting diodes?

[anotherjim]

I call "bog standard" a 20mA LED, because that's the general maximum current rating. Now you have a wide variety of high efficiency/high brightness types but the original 20mA are still around - they are the kind you get in multi packs of 5mm/3mm/Red/Yellow/Green for experimenters/education sold by the likes of Velleman because they are cheap. Buy a pack -  it'll last you long time.