VT101 8085 CPU Fault

Mouse mouse at Rodents-Montreal.ORG
Sun Feb 22 15:04:32 CST 2015


> I was wondering about that - isn't the startup current, when the
> supply is first turned on, going to be substantial, especially with
> the larger caps?

Generally, yes.

> Any chance that could harm the DMM (or am I too used to old
> mechanical meters? ;-), or are they pretty well protected against
> over-current situations?

I would imagine it depends on the meter; I don't know such things
enough to know which kind is commoner.  I would tend to be paranoid
about it, so either I would charge the cap up directly and then
disconnect it and reconnect it through the meter, or I would hook an
SPST in parallel with the meter and make sure it's closed at initial
power-up.

Alternatively, I'd use something like a 1 ohm 1 watt resistor in series
and then hook a DMM set to voltage across that.  But if the leakage is
down in the microamp range, that may work poorly to not at all (though
something like that is what current ranges tend to actually be
implemented as, AIUI).

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