MOT series

[Ruben Schoonbaert]

Hey, so im planning on making a project using a dual mot powersupply, anyways i want to make sure i'm doing this correct.
Does anyone see any mistakes on this circuit (i'm not sure if i need to ground it or not ( see red).

 

[DerStrom8]

No, that is not correct. And to be honest, if you have to ask then you should not be doing this. MOTs are EXTREMELY dangerous. You won't get a second chance. You hook up something wrong and you'll die instantly without knowing anything happened.

 

[unclejed613]

with the amount of current available from a MOT you're playing russian roulette, especially if you aren't sure what you are doing. DerStrom is right, you won't know what hit you. do not continue your project without expert help. (in person, not over the internet)

 

[Ruben Schoonbaert]

How am i playing russian roulette with a 5 foot chicken stick with 2 mot's im planning to submerge in mineral oil? Wearing rubber gloves and insolation shoes, i appreciate your concerns but i'm always verry carefull when handeling hazardous voltages.
I would get "expert help" but since i have no idea who id need to ask the internet is my best shot.

 

[Ruben Schoonbaert]

MOTs are EXTREMELY dangerous.

agreed but im not in close proximity when its running

You hook up something wrong and you'll die instantly without knowing anything happened.

I dont see how hooking up mots incorrectly will do anything else but trip the breaker or burn the transformer.

 

[DerStrom8]

agreed but im not in close proximity when its running

I dont see how hooking up mots incorrectly will do anything else but trip the breaker or burn the transformer.

My point is it's critical to be over-cautious when playing with high voltage and high current devices. For example if something is connected incorrectly, you could go to plug in the MOT and have high voltage jump to the mains cable you're holding in your hand. It's not likely, but anything's possible. You can't rule anything out.

Anyway, I was at work earlier and was distracted, and misread your schematic. Yes, it will work the way you drew it. Don't forget to ballast your MOTs though. As I am sure you are aware, they are not inherently current-limited.

 

[Ruben Schoonbaert]

My point is it's critical to be over-cautious when playing with high voltage and high current devices. For example if something is connected incorrectly, you could go to plug in the MOT and have high voltage jump to the mains cable you're holding in your hand. It's not likely, but anything's possible. You can't rule anything out.

Anyway, I was at work earlier and was distracted, and misread your schematic. Yes, it will work the way you drew it. Don't forget to ballast your MOTs though. As I am sure you are aware, they are not inherently current-limited.

I have this transformer from an old stereo, do you think this would work as a ballast or should i just use another mot as ballast?

 

[DerStrom8]

I have this transformer from an old stereo, do you think this would work as a ballast or should i just use another mot as ballast?

Personally I would use another MOT. They're rated for higher power than most of the types of transformers you'd find in old stereos. I usually put a third MOT with the primary in series with the HOT wire on the mains cord, and short the secondary coil. This serves as a pretty decent ballast.

 

[unclejed613]

i'm always verry carefull when handeling hazardous voltages.

sorry, i'd rather you be alive to be upset at me, than not alive. we do get a good amount of posts here that sound like "i'm a total noob and want to build an X-ray machine as my first project" (or even worse, it's already built and they want to know how to tell whether it's working or not).

you didn't mention if the transformers are identical or not (same make/model/part number). to get the voltages to add, you might want to check the phasing of the secondaries. some secondaries are grounded internally in the transformer, so your ground point for that particular transformer can't be changed. if the secondaries are internally grounded, and grounded at the same end, you might need to wire the two primaries out of phase, rather than in phase.

 

[Ruben Schoonbaert]

sorry, i'd rather you be alive to be upset at me, than not alive. we do get a good amount of posts here that sound like "i'm a total noob and want to build an X-ray machine as my first project" (or even worse, it's already built and they want to know how to tell whether it's working or not).

I'm not planning on building an xray since i don't want to die from berylliosis and/or cancer.

Also although being a big step up from zvs flyback drivers i'm not a complete noob regarding high voltages

i also work with mains voltage on a day to day basis and i have only gotten zapped like once(wasen't even my fault)

The current mots i have are different models( although similar ) but ill be looking into finding a 3d thats the same as one of the previouse models and use the other one as ballast.

(also i'm not upset, very gratefull for a comunity who cares about my wellbeing)