New Classic Finds and etc. (Long)

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Tue Jan 27 17:19:11 2004

Could you please get your mailer to (a) put in newlines after 72
chracters and (b) to use some sensible quoting convention. It's hard to
follow who says what here!


>
> Funny... I powered a very old typewriter with more than 50V over the
> stated rating. The rating for the Amps matched EXACTLY and it ran like a

A meaningless statement!. What was the correct voltage? If it was, say,
200V, then probably 250V would have been OK. If it was, say, 12V, I would
be very supprised if 62V did no damage.

And what is an 'old typewriter'. Electromechanical? Such devices tend to
be a lot more tolerant of overvoltage than modern electronics.

> dream until recently when some water got into the PSU, BTW this is a
> WELL regulated unit... refusing to be off by more than half a volt. I
> did the same with a more recent device (a digital thermostat used to
> control certain devices in my bedroom)... and recently that device fried
> when I had to get a new PSU. The power rating was still 50V over rating

What voltage did the digital thermostat require? I would assume, if it
used an external PSU, then it would be something like 12V. Are you
seriously saying it ran fine off 62V?

 
> and I got one that was just a little over the rated amps (I forgot to
> check) and plugged it in... when I turned it on all hell broke loose.
> What do you have to say to that? *mumbles* buncha smartass

So far you've told me very little. You've not given the actual voltages
involved -- I'll say it again, a device expecting 200V would probably be
OK with 250V in a lot of cases, but I doubt _any_ chip designed to run
off 5V would stand 55V. You've not told me anything specific about the
devices.

> know-it-alls... why in my day... *continues inane rambling*

I don't claim to know it all. I know there's a heck of a lot I don't
know. But I also suspect I've worked on more PSUs than you've ever seen.
And I have a darn good idea about what happens when an approximately
constant volrage PSU is connected to various loads.

-tony
Received on Tue Jan 27 2004 - 17:19:11 GMT