'the relay circuit - 1N400X re 1N4148'
|Advice: Always buy and use 1N4007's.
Ignore this advice if you are making 1000's of a single product or
NEVER read a component wrong.
They are about the same price as all the other 1N400X series
(sometimes less) and that way you know that the diode you use
anywhere is always going to be 1000 volt rated. Having a 1000 volt
part in a 50 volt circuit will do no harm. Having a 50 volt part in a
500 volt circuit will cause you grief.
What's the chance that the 1N4001 that you pick up will fool you into
thinking it's a 1N4007 when you are rushing to get something done?
A very interesting use for 1N400Xs is not at all intuitive.
In circuits running at very low currents, as I recall, a 1N400X will
have both lower reverse leakage current and lower forward voltage
drop than the mainstay 1N4148. It can therefore be BETTER to use the
400X in a ma (or even microamp) level circuit.
From: John Smith <IAFRICA.COM> jselect
To: MITVMA.MIT.EDU < PICLISTMITVMA.MIT.EDU> PICLIST
Date: Wednesday, January 06, 1999 7:36 PM
Subject: Re: the relay circuit
>From: Michael J. Ghormley
>>Is the 1N4007 better than the 1N4001? I thought that their current
>>ratings were about the same, but their PIV was just higher (no
>>handy). Am I wrong or is there another reason for the 1N4007?
>None of the my suppliers here in South Africa stock the 4001, they
say it is
>more expensive than the 4007 ( which has always been the bread and
At 22:54 6/01/99 +1300, you wrote:
>Advice: Always buy and use 1N4007's.
>Ignore this advice if you are making 1000's of a single product or
>NEVER read a component wrong.
> Russell McMahon.
One slight caveat to watch. I got a whole stack of 1N4007s to use
in a circuit board designed for 1N4002s. The lead thinkness was
different and I had a very difficult time inserting the 1N4007s.
Eventually I put the 1N4007s aside and went back to the 1N4002s.
Hi to y'all,
the mentioned diode parameters are OK, that is, the main characteristic for
differences are the Peak Reverse Voltage, ranging from 50 V to 1000V for
the 1N4001 thru 1N4007 in different steps.
Now some may ask: Why the H*** do I need seven different types when one
would cover both the 50 V and 1000V PRV??
The answer is as follows: The 1000V are a lot harder to block than 50 V. So
the zone in the semiconductor crystal that is free of electrons/holes
respectively has to be about 20 times bigger to prevent breakdown of the
barrier. BUT as a sideline, also the AC characteristics of the diode are
slower due to the larger crystal barrier needed to block the high voltage.
So it is a choice limited by the PRV and the tradeoff in AC performance
that leads to the usefulness of e. g. a 1N4003 in a certain application.
This becomes even more important when working with Schottky diodes. These
often have very low PRV, sometimes only 20 V. If you choose a 60V model
instead, you will have severely limited switching performance compared to a
similar 20V model...
My 0.01 EURO's worth...
jf @ detektor.de
Larry G. Nelson Sr.
Remember that the higher voltage diodes are slower and have more junction
capacitance. For small power supplies off of 60hz probably not an issue but
in some applications it can make a difference.
At 10:54 PM 1/6/99 +1300, you wrote:
Larry G. Nelson Sr.
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