Normal
Re: Failure rateVery high tech solution. I had a spare variac kicking around, so I put it inline temporarily with the AC to see what input voltage would yield a good margin between in and out voltage on the regulators. It turns out 90VAC is about right, providing a voltage differential of about 4 volts between the in and out terminals of the regulators. Seeing all was good, I just left it connected specifically for that.
Re: Failure rate
Very high tech solution. I had a spare variac kicking around, so I put it inline temporarily with the AC to see what input voltage would yield a good margin between in and out voltage on the regulators. It turns out 90VAC is about right, providing a voltage differential of about 4 volts between the in and out terminals of the regulators. Seeing all was good, I just left it connected specifically for that.
