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crackle · 15th Sep 2018, 8:07 am

I use an isolation transformer, variac and lamp limiter.
But the Isolation transformer is connected only to my service equipment and soldering iron.
I prefer to rely on the 30mA earth trip also connected to my "test" socket, where I connect the radio under repair, to safely disconnect the supply should I touch something I shouldn't have in the radio.
The trouble with isolation transformers is they don't protect you if you get a shock from a live point to chassis in an AC/DC set.
I found this out the hard way. The sustained shock I got cauterised my skin so deep it took more than 6 months to heal, I still have the scar.
As per the excellent advice in the OP my lamp limiter is immediately before the "test" socket which can be quickly turned off with a double pole isolation switch. The lamp limiter also has a bypass switch.
I am not pretending this is the best practice, so copy at your own risk.
Maybe if you are a qualified person you may like to comment on the arrangement.
thanks
Mike

15th Sep 2018, 8:07 am	#7
crackle Rest in Peace Join Date: Mar 2011 Location: Basildon, Essex, UK. Posts: 4,100	Re: Lamp limiter plus Variac tip I use an isolation transformer, variac and lamp limiter. But the Isolation transformer is connected only to my service equipment and soldering iron. I prefer to rely on the 30mA earth trip also connected to my "test" socket, where I connect the radio under repair, to safely disconnect the supply should I touch something I shouldn't have in the radio. The trouble with isolation transformers is they don't protect you if you get a shock from a live point to chassis in an AC/DC set. I found this out the hard way. The sustained shock I got cauterised my skin so deep it took more than 6 months to heal, I still have the scar. As per the excellent advice in the OP my lamp limiter is immediately before the "test" socket which can be quickly turned off with a double pole isolation switch. The lamp limiter also has a bypass switch. I am not pretending this is the best practice, so copy at your own risk. Maybe if you are a qualified person you may like to comment on the arrangement. thanks Mike Last edited by crackle; 15th Sep 2018 at 8:14 am.