>
>Using a high voltage current limited source is also common practice to
>increase the switching speed of stepper motor driver stages. I was taught
>that in the early 80's!
>73 Fraser G4BJM
>
ok
>-----Original Message-----
>From: owner-amps@contesting.com [mailto:owner-amps@contesting.com] On Behalf
>Of Peter Chadwick
>Sent: 10 November 1998 14:20
>To: 'amps'
>Subject: Re: [AMPS] Fw: [TenTec] Titan info
>
>
>Rich says:
>
>>Curiously, I know of no amplifier manufacturer
>>who uses a 110 - 160 volt current limited source for such relays.
>
>
>I don't think it's curious, Rich. It's a matter of age and experience, and
>few people need to worry about speeding up relays these days. SO when they
>do, they can get a bit lost. The classic place where current limited high
>voltage supplies were used for speeding up electromagnets was in
>teleprinters and polarised telegraph relays. If you went into college after
>about 1965, you wouldn't have learnt about this.
>
However, it wasn't directly taught in the college I went to [Cal Poly /
San Luis Obispo]. I did learn about the way current increases in an
inductor and the way voltage increases across a capacitor, which is key
to the solution of the speed problem. The practical side I learned by
reading the Jennings catalog and measuring various sped-up relay speeds
with a dual trace oscilloscope - when I was trying to design a high-speed
switching circuit that would beat the fastest radio on the market.
.
>Isn't there some saying about age and experience will always do the dirty on
>youth and enthusiasm?
>
- - Age is a case where more is not necessarily better. In his second
term, President Reagan managed to sell a terrorist state (Iran)
state-of-the-art anti-tank missiles. Saddam understandably got pissed
and the U.S.S. Stark paid for Reagan's mistake. . . Eventually, Reagan
began to recount WWII American propaganda stories as if they were
actually true although they were purest bovine feculence. .
>
- later, Peter
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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