Electronics > Beginners

1N34 Diode Schematic included

<< < (4/5) > >>

rstofer:

--- Quote from: johnkenyon on October 31, 2018, 08:00:44 pm ---
--- Quote from: rstofer on October 31, 2018, 06:15:04 pm ---Given that the 2 diodes just work as a half-wave rectifier to turn on the transistor when the crystal starts oscillating, I would think any small signal diodes would work.  Try 1N914 or 1N4148.

--- End quote ---

Looks more like a half wave voltage doubler to me, but like you said, any small signal diode would do.

--- End quote ---

You are absolutely correct, it is a Greinacher Voltage Doubler circuit:
https://en.wikipedia.org/wiki/Voltage_doubler

David Hess:

--- Quote from: rstofer on October 30, 2018, 04:14:55 am ---How does the forward voltage drop of a germanium diode compare to a Schottky diode?
--- End quote ---

Germanium diodes have about a 25% lower forward voltage drop than common small signal silicon Schottky diodes.


I have yet to find an application where a 1N270 would not work in place of a 1N34A and both are suitable for RF and switching applications.

Simon123:
The modern 1n34 is similar to modern 1n60, which is schottky diode ...
http://www.kdiode.com/admin/diotech_file/1N60~1N60P.pdf

You can try getting 1N5711, which is very fast and cheap schottky diode ...

alsetalokin4017:
Well... perhaps "It depends".

An interesting exercise is to connect your Diode Check DMM (I'm using the Fluke 87-III) in series with another DMM in the mA range. Then check a bunch of diodes.  First just check readings with the test leads shorted (to see the burden of the mA  meter); in my setup the Fluke is indicating about 0.013V and the mA meter is indicating slightly over 1  mA. Now insert a diode and read the Vf at the indicated current. It appears that the Fluke is using 1mA as the current for the Vf determination.

Test some Schottkys, some Si rectifiers, Si small signal diodes, and of course germanium 1n60 and 1n34A if you have them. (I was able to find two 1n270 pulls and they tested the same as my "known real" 1n34As in this test.)

jh15:
I just bought what was said to be 1n34 diodes from ebay.
Description said true 1n34.

They are clear glass with a whisker seen.

Junk! they all tested around .8 .9, or many open volts on my 8960.

Called black banded. The other ones marked red band not tested yet.

They come in a screw top test tube package.

I'll dig out my my Tektronix 575 curve tracer once I get the strength.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod