Unusual functions of cheap parts

A high-voltage optocoupler; cool.

I've posted a schematic for a hv opamp (400 v p-p) that uses two optoisolators as the output push-pull stage... it's very cheap and simple. A higher-voltage photodetector, like a glass power diode, sounds useful, too.

I worked once with a company in Southern California that had a neat gadget: it was a truncated cone of silicon with gold contacts on the base and the flattened apex. It would stand off something like 5KV until you whacked it from above with a laser, illuminating all the sides of the cone, whence it would conduct hard. I think they went out of business, though; it was pretty obscure.

John

While many companies* are making 1n4007G glass-passivated diodes, it appears they all cover the glass with plastic. I wonder... where one can get a 1n4007 with an all-glass package these days?

• Including unusual semiconductor manufacturers, like: Won-Top, Bytesonic, Leshan Radio, Formosa Microsemi, Gulf Semiconductor, Dachang Electronic, Goodwork Semiconductor, etc.

--
 Thanks,
    - Win

Very interesting. The 1N4007 seem to be very versatile devices. They are available with a SOD-57 glass envelope, too (1N4007G?). These are fairly well photoconductive. When illuminated by a high efficiency IR LED (HSDL-4230 or so) current transfer ratios of 0.001 can be achieved. Not too much, but with two LEDs 100uA of photocurrent is obtainable. This is OK for a pass element in an "electrostatic" power supply for e.g. electron or ion lens systems.

--
mfg Rolf Bombach

I've got a few 1N4003 and 1N4004 diodes with all-glass packages but I'm not sure how recent they are. They have the (older?) Fairchild logo of an italicized "F" with the middle stroke extending on both sides of the vertical. I'm about 90% sure these came in one of those "20 rectifiers for $2" packages from Rat Shock, so who knows how old they really are. The bodies are about 2.5 mm diameter by 4 mm long. Inside the glass, the ends near the leads are orange, with a clear strip less than 0.5 mm wide near the middle.

Testing them with the "diode check" on a $40 multimeter and either a 40 watt clear globe lamp or a TV remote control doesn't show much photoconductivity, but I suspect I would need to look a little harder than this to see it.

Matt Roberds

How many do you need, and can you use ones pulled from PC boards? I may have some left that I pulled from damaged boards.

--
Been there, Done that, I\'ve got my DD214 to prove it.

Michael A. Terrell
Central Florida

Maybe so, but this wasn't a GTO, it was a bulk-effect device, blindingly fast.

Can an opto-triggered GTO be turned *off* with light?

John

One or two may be enough for proof-of-principle measurements.

--
 Thanks,
    - Win

I've done that with 1" oak dowel.

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | "Winners never quit, quitters never win", Jack Bradley Budnik ~1956

I don't know, I save all my scrap ;-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | "Winners never quit, quitters never win", Jack Bradley Budnik ~1956

I thought optical triggered GTOs were still in business??

regards - Henry

"John Larkin" schrieb im Newsbeitrag news: snipped-for-privacy@4ax.com...

Hello Henry,

Six sawed off pieces of the pole of a busted market umbrella allowed me to move a 1/2ton piece of furniture all by myself.

Oh wait, wrong category....

Regards, Joerg

I'll see if I can find a couple for you.

--
Been there, Done that, I\'ve got my DD214 to prove it.

Michael A. Terrell
Central Florida

Hello Jim,

But if you bought those I bet my solution was cheaper. About one cent worth of elctricity to saw it ;-)

Regards, Joerg

I've done it with sheer adrenaline (I'm 6'0", 150#) after watching three big bruisers horse around and get nowhere with an air conditioner that was IN MY FUCKING WAY!!! I stomped up, said "MOVE IT!", grabbed a corner, shoved hard and walked past. And no, I didn't so much as bend a fingernail.

Mark L. Fergerson

PS I once used a $150 multimeter as a non-resettable fuse, but I don't think that's what the OP had in mind...

For some reason, this brings to mind one of todays Top Nooz stories - some woman who was jogging in the park was jumped by some guy who wanted to assault her and she kicked the shit out of him. But they noted that she was 6' and about 140#, and he was 5'6", 120#. It was actually kinda refreshing to hear about someone defending herself, but how stoopid do you have to be to attack somebody that's twice your size? ?:-/

Cheers! Rich

I got mad one day when i was 20 and picked up a Pontiac 389 short block.

--
Been there, Done that, I\'ve got my DD214 to prove it.

Michael A. Terrell
Central Florida

Back when one of my tasks at Fluke was to interview college recruits, I was asked to describe my job as an Analog Design Engineer. My answer:

"To design precision instruments using cheap, junk parts."

A tip of the hat to Norm Strong...

Steve.

--
Steven D. Swift, novatech@eskimo.com, http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC.      P.O. Box 55997
206.301.8986, fax 206.363.4367  Seattle, Washington 98155 USA

OK, I'll trade you some 1500V damper diodes, with datasheets. They should be interesting additions to your parts inventory.

--
 Thanks,
    - Win

Old thread, but still worth answering.

• Small signal germanium transistors in glass packaging, (OC45 comes to memory, TO1 package,) make good photodetectors after scrapping the paint.

• Zener diodes are good noise generators (This is widely known and used.)

• Some small (toy) dc motors wired in series with a speaker make good siren sounds.

Roberto Waltman

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