Refurbishing An Old Variac

[@MadeInMichigan]

I got one I've had for like 20 yrs I need to do the same thing to. Nice to see someone walk through it.

[@MetaphysicalEngineer]

A little bit of care now and then and these units can almost last forever. Glad you found this video helpful! How much and what kind of use does your unit see?

[@MadeInMichigan]

@@MetaphysicalEngineer Lately, I don't use it all that often. It mostly does duty as a variable DC power supply when I need 100-150V for something. Occasionally, I need 24-48VAC to test a small drive or something.

[@DonNoddingPolitely]

Hey man. Thanks for the vid. I love all that old kit. I don't know if it means anything, but... I clicked the "Like" button but the like counter stayed at zero???

[@DonNoddingPolitely]

Reloaded page and like counter is working. Chillax

[@MetaphysicalEngineer]

Thanks for the kind words! Hoping to keep this gear going for many more years! That's quite strange about the comments! Let me check the settings on my end.

[@MetaphysicalEngineer]

Sometimes KZbin can take a sec to catch up. Seeing it on my end now!

[@thecorruptedbit5585]

My friend got one of these for 20 bucks. He's looking to sell it but I'm a bit too scared of what these are capable of

[@MetaphysicalEngineer]

You’re right to be cautions. A big danger with these is lack of isolation and large amounts of current available, so just as much risk of shock or electrocution as if you were directly applying line voltage. Requires the same safety procedures and common sense as working with any other live, mains powered equipment. What would you be using it for if you did end up buying after all?

[@thecorruptedbit5585]

@@MetaphysicalEngineer I don't really know, to be honest. Debugging analog electronics? I'm an ECE student so I see it as a tool that I can play with AC with, not that playing with AC sounds very safe. I know a guy who's more into analog and power electronics than I am (he's collected microwave transformers for "eventual use"), maybe he'll get the variac instead. I'm curious what he'd do with it!

[@MetaphysicalEngineer]

If you’d be reconditioning things like amplifiers, a variac is an extremely handy tool. Combine with a ballast controller like I had in the load test and an incandescent lightbulb to carefully power up equipment that’s been sitting for a while. Or in general on equipment where you suspect damage or don’t know the history of. Slowly bringing up the voltage will allow things such as power supply capacitors to reform instead of punching through. The lightbulb will limit fault current and give a handy indication of problems if it glows brightly. Combined can prevent avoidable problems like exploding input stages, or stop a minor fault from causing a cascade failure. Other uses involve testing a design’s tolerance of line voltage going out of spec. I have a few much older videos where I used this device for destruction, or for science, such as running a fluorescent tube on variable voltage DC with a lightbulb for a ballast.

[@SAROTHIBISWAS-e8n]

I have seen your KZbin channel and discord that you are not getting more and more views. So if you are interested to work with me or interested get a free consultation then you can share your detail here so I can reach you.

[@MetaphysicalEngineer]

Unfortunately, any advice you’d be able to provide is already available for free, and SEO optimization is largely irrelevant with how youtube works now. But you’ve interacted with this video by commenting, so you’ve already helped me plenty :)