[GreenKeys] Loop Supply

[Ralph Mowery]

That was my understanding too about the magnets.

 

 

Looking at the scope pattern it is hard for me to tell how long it takes to
reach close to 90 % of the current.  If it takes several milliseconds, that
could be the problem.  I looked at the data sheet for the optical isolator
but could not determine  the specks are for the delay time  at higher
voltage and current.   Some optical isolators are somewhat slow.  Remember
you only have 22 miliseconds to deal with and if you waste 2 or 3 on and 2
or 3 off you are using up a good bit of the time.

 

 

From: greenkeys-bounces at mailman.qth.net
[mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of Xavier Andrieu via
GreenKeys
Sent: Friday, December 14, 2018 3:59 PM
To: 'John, W9DDD'; greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] Loop Supply

 

My understanding was that selectors with "pulling magnets" can only be used
at 60 ma and selectors with "holding magnets" can be wired in series or in
parallel and then run either 60 ma or 20 ma. (see
www.baudot.net/gil/tty-machines/M15-KSR.htm).

 

Xavier

 

De : greenkeys-bounces at mailman.qth.net
[mailto:greenkeys-bounces at mailman.qth.net] De la part de John, W9DDD
Envoyé : vendredi 14 décembre 2018 21:34
À : greenkeys at mailman.qth.net
Objet : Re: [GreenKeys] Loop Supply

 

I'm foggy about the specifics of the 15 (about 57 years of cobwebs), but you
show in your drawing what appears to be magnets wired in series instead of
parallel, which would be normal for 

 

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