Rolf_B wrote...

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 ...

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

In sci.electronics.components Winfield Hill wrote:
Rolf_B wrote...
[1N4007] are available with a SOD-57 glass envelope, too (1N4007G?).
These are fairly well photoconductive.

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?

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

On 18 Dec 2005 19:38:19 -0800, Winfield Hill
wrote:

Rolf_B wrote...

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 ...

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.

Or use a differnt diode in a glass case. The PN junction makes a
decent small area photovoltaic cell (transistors too).

FYI: if your using 1n4007 for a varactor, light impinging on glass
versions will drive you nuts ( Florescents will give AC hum
modulation) and lower the Q.

Allison

Winfield Hill wrote:

Rolf_B wrote...

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 ...

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

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

" bravely wrote to "All" (19 Dec 05 07:25:41)
--- on the heady topic of " Unusual functions of cheap parts"

mr From:
mr Xref: core-easynews de.sci.electronics:311430
mr rec.radio.amateur.homebrew:89926 sci.electronics.components:104476
mr sci.electronics.design:532313


mr In sci.electronics.components Winfield Hill
mr wrote: Rolf_B wrote...
[1N4007] are available with a SOD-57 glass envelope, too (1N4007G?).
These are fairly well photoconductive.

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?

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

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

mr Matt Roberds


Germanium diodes like a 1N34 in glass case are quite light sensitive.
Some LED's are too and IR emitter LED's are quite sensitive to IR.

A*s*i*m*o*v

I thought optical triggered GTOs were still in business??

regards -
Henry


"John Larkin" schrieb im
Newsbeitrag ...
On Sun, 18 Dec 2005 21:33:52 +0100, Rolf_B
wrote:

John Larkin wrote:

A 1N4007 can also be used as a drift step-recovery diode and as a
plasma avalanche diode. Together, two can generate a kilovolt edge
with a 100 ps risetime.

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.

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

On Wed, 21 Dec 2005 00:31:35 +0100, "Henry Kiefer"
wrote:

I thought optical triggered GTOs were still in business??

regards -
Henry


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

Michael A. Terrell wrote...

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.

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


--
Thanks,
- Win

Hello Henry,

Do you know of other interesting devices or circuits good for misuse?


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

http://www.analogconsultants.com

Winfield Hill wrote:

Michael A. Terrell wrote...

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.

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

--
Thanks,
- Win

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