Chinese Germanium 1N34

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Hmm my post disappeared. OK I reverse biased an osi opto-electronics PIN-3CD (With 100 k ohm to limi t the current.) It didn't avalanche till ~150V. But the avalanche current was independent of the photo current... Like it was avalanching at the edg es or something. I've had "edge issues" with this PD in the past.... I nee d some other small PD's.

George H.

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mit the current.) It didn't avalanche till ~150V. But the avalanche curre nt was independent of the photo current... Like it was avalanching at the e dges or something. I've had "edge issues" with this PD in the past.... I n eed some other small PD's.

Update.. I did find some other PD's They all seemed to avalanche around 100-150V. With the avalanche "channel" not coupled with the photo "channel".

Which I guess is why you have to pay more for APD's... George H.

Guard ring maybe?

On Wed, 18 Feb 2015 20:26:02 +0530, "Pimpom" wrote as underneath :

I have used since 2002 a couple of 3mm hibright red LEDs like this as indicators but running them at less than 0.00005A (240v mains R series at 470K) nothing like your figures 1-2mA. So this works fine just for indicators but I would be wary of doing this at anything like full LED brightness. Output looks same as when installed.

I killed one with only 9V

Must have been without a series resistor or other current limiter.

did that with a clear LED using a 1M R as a ballast .

It gave some interesting results at around 25V

Jamie

Me too! (it all started on SEB after all.)

The leds are from purdy electronics AND113R and AND114R

For best results as a detector get the 113R "clear" sand down most of the plastic till you get near the wire bond and then polish out the scratches.

George H.

do you also use a file on carbon composite resistors to get the value you need when in a pinch, too? ;)

Jamie

On Thu, 19 Feb 2015 08:02:35 +0000, Charlie+ wrote as underneath :

snip

Sorry correction on checking circuit - used these LEDs like this since

I've heard about filling carbon composites, but I've never done it. (almost all 1% metal film.. though a few CC used for the non-magnetic properties)

George H.

George Herold prodded the keyboard with:

Hi George, You can flame polish the plastic. Just touch the plastic into a small flame until it starts to melt, it only takes a couple of seconds or so. I use this method on the lathe to polish the lens ends on 1/2" perspex rod.

Oh thanks I hadn't thought of that. (I use a bit of spit as a temporary solution.)

George H.