The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: firstname.lastname@example.org (john jardine)
Subject: Re: want a list of R value E6 E12 E24 E48 E96
Date: 9 Nov 2002 06:48:44 -0800
References: <3DCC0BE7.BEDAFF5@fanwap.com> <3DCC8745.4E4757C7@mfi.net>
NNTP-Posting-Date: 9 Nov 2002 14:48:44 GMT
"Michael A. Terrell" wrote in message news:<3DCC8745.4E4757C7@mfi.net>...
> John Jardine wrote:
> > R. Lewis wrote in message
> > news:email@example.com...
> > >
> > > "cpemma" wrote in message
> > > news:firstname.lastname@example.org...
> > > > John Jardine wrote:
> > > > >
> > > > > From E24 on ...
> > > > > Why can't they make some ** really useful** values like
> > > > > 400,500,600,700,800,900 instead of slavishly keeping to that 'log
> > > > > increment' formulae.
> > > >
> > > > You mean the E1 series? ;)
> > > >
> > >
> > > Funny how old wives tales about log series for resistors hangs on.
> > > Where did it come from?
> > >
> > > (Pleeeeeze do not explain that the resistor series follows a logarithmic
> > > progression)
> > >
> > >
> > I've no idea of the details but remembered it from a long discussion in
> > Wireless World mag', many many years ago. IIRC a German contributor actually
> > quoted the series generator formula and the relevant DIN national standard.
> > Also, (I am told) one of the BS standards uses an identical version for
> > electric motor 'preferred sizing' purposes.
> > Also found this which makes a little sense.
> > http://www.sxlist.com/techref/resistors.htm
> > Tell us more ;-) ...
> > How are those weird E96 values computed? and why can't I have a 9 ohm 1%
> > resistor?.
> > regards
> > john
> You can order any value you want under the classification of, "As
> Marked", where the manufacturer will sort them to your spec but you'll
> pay dearly for this service.
I've been surprised at how cheaply they can be specially manufactured.
Even at the 1000 off level. Look at say the internals of Tek and HP
kit and there's not a commercial resistor in there. They must do their
designs on paper and whatever result came off the designers calculator
gets manufactured as a resistor!.
I've a drawer full of 51 ohm resistors. Not one of them will end in up
in kit because the calcs suggested a 51 ohm (ish) value. Nearly all
will end up being used as 'pretend' 50 ohm resistors. Numerous times
I've had to stick 2x100ohms in parralel to get some kind of 50ohm
How many 10:1 voltage dividers end up using a poor 910k in series with
a 100k cos a 900k isn't made?. Any pretense at accuracy then requires
the addition of a twiddler pot.
Non-inv x10 op-amps can't be done for the same reason.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup