got two identical transformers from ups battery backups... thinking about making an isolation transformer, any better ideas?
got two identical transformers from ups battery backups...
got two identical transformers from ups battery backups... thinking about making an isolation transformer, any better ideas?
I replaced the secondary on a transformer I had with a few turns of 8-10 AWG and attached these to two copper electrodes. Allowed me to spot weld a stainless steel pan. Look it up on yt if you're interested. My transformer was around 1kW, which looks much more than what you have, so I don't know...
i might do this. maybe. i need to make a solid li-ion battery pack. so... have to do it right. maybe its better to buy i dont even know which youtube tut to follow lol.
I am interested in maybe doing a spot welder type thing sometime down the line, but figure I'll just use a MOT for that as its more difficult to find two identical microwaves on the side of the road.
I’ve been collecting MOTs for about 10 years to gather as many matching/identical transformers as possible.
I now have 31 unique MOTs and no matching ones, and they’re heavy and bulky. My wife also thinks I’m a literal moron and should seek help.
>31 unique MOTs and no matching ones
your wife is right, you are a moron
you dont need exact matches, just approx power levels if you put them in parallel
say you have two 1000W units with 120V primaries,
you get to determine the turns in the secondary, so you have 2 units with pretty much everything identical
also, if you put the secondaries in series, it's another way of doubling power, where they DONT HAVE TO MATCH at all
(just careful how you wire them in series: one way the voltage adds, the other way it subtracts)
solid paperweight collection
Just based on the size, I'd think that is probably sub 250 watts.
just looked up transformer on google for that pic lol, pic in
is closer
I built one of those.
forgot to mention you should be able to get at least 10 amps out of it.
Should have a tap in the middle in case you need 24 (or 12) volts.
Nice MOV.
funny someone else beat me to this idea probably going to give it a shot. curious what do you use it for or whyd you want to make it?
I fix old tube radios, they have hot chassis and you can get electrocuted easily if not careful. an isolation transformer keeps you from getting the full mains treatment. you can still get shocked but you aren't as likely to since there is no path to ground the neutral and hot are their own circuit and neither is tied to ground. so can't get zapped if you touch something live and then something grounded.
also protects equipment like oscilloscopes from the high voltages of old radios.
yeah i originally wanted to build one to power things that have an earth that I needed to look at with an oscilloscope. The more research I do though the more hesitant I am. For awhile I didn't have an isolated power supply so almost every circuit was powered by random wall warts i could find. Now it seems like a more niche thing I wouldn't really have a need for as I don't work on anything with a hot chassis.
A use case I did maybe come across was replacing a battery on an hp3478a multimeter. Removing the battery when unpowered would result in the loss of calibration data, but soldering on a powered machine would sort the battery through the tip. Would an isolation transformer powering the soldering iron, or even the multimeter, be within the realm of the intended use for an isolation transformer? Just trying to get a better idea on how these can be used to protect oscilloscopes.
>be within the realm of the intended use for an isolation transformer?
yes
You're not getting bit with one hand technique.
I use 100x probes.
you most certainly can get bit with the one hand technique. I accidently grabbed on to a series of connections (with one hand) that had different voltages going up to 450v.
and it hurt. an isolation transformer is a must for old radio work.
your 100x probe won't save your oscilloscope.
>whyd you want to make it?
forgot to mention.
because for a short time I was recycling computer equipment and had a pile of old APC UPS's.
I built power supplies, battery chargers, and an isolation transformer.
the amount of amps your isolation transformer can put out is similar to it's maximum input voltage. so if it has a 15 amp circuit breaker on the back then it should have no problem putting out 10 amps. if it has a 10 amp then 8 amps should be no problem.
I saw an old APC home computer UPS in goodwill the other day. $95.00.
Guess they go by weight. Must be valuable!
that goodwill is quoting ebay prices. I've gotten them for $5.
what size UPS did they come out of?