Good evening,
This is a little project I put together today and want to run it by you guys for your purusal.
Years ago I came by an Electro magnet used on "Mag Drills" , which are industrial drills used to drill holes in steel beams in the steel fabrication buisness. These drills have a very strong electro magnet on their base in order for them to be set in any position to drill holes, very usefull devices.
This particular one was laying in a pile of junk in the welding shop where I worked, the drill was completely destroyed and discarded into the junk pile, etc.
Well, I saw the magnet and knew that I'd like to play with it one day.
Finally having all my honey-do's caught up (and finally finished that scoreboard project (tx's to Mr Gibbs)), I decided to hook it up and have a really nice (strong) magnet to play with.
Only thing I knew about it was that it's resistance was 120 ohms, had no idea what the voltage requirement was.
I did a search on the internet and luckily found a schematic for one.
Apparently, the one I found (see attachment) just requires full wave rectification.
So, I conclude, perhaps this one is similar.
I devised a circuit and have implimented it, and, it works great, but, after about 10-15 minutes the magnet starts to get warm, and warmer.
This tells me that I am somewhat exceeding it's amperage rating.
Measuring the voltage I get 146VDC which corrolates to 1.2 amp.
Am thinking it probably uses only 1 amp, so am proposing adding a 26 ohm 50 Watt resistor
in series with the coil, that should drop the current down to 1 amp.
Then again, I'm thinking that's not a lot of drop, it'll probably require a bit more resistance to drop it down further, so that, I could let it run for considerable time without it heating up (as it does in real life situations using a retail drill, etc)
Any observations and opinions would be appreciated.
Am fully aware of the danger messing with the "mains" .........
I used heavy duty FBR and Cap just because I had them, etc......
Retail drill schematic didn't come out too clear but, is readable, neutral line seems to be missing on pic.......
Tx's
Oxbo
This is a little project I put together today and want to run it by you guys for your purusal.
Years ago I came by an Electro magnet used on "Mag Drills" , which are industrial drills used to drill holes in steel beams in the steel fabrication buisness. These drills have a very strong electro magnet on their base in order for them to be set in any position to drill holes, very usefull devices.
This particular one was laying in a pile of junk in the welding shop where I worked, the drill was completely destroyed and discarded into the junk pile, etc.
Well, I saw the magnet and knew that I'd like to play with it one day.
Finally having all my honey-do's caught up (and finally finished that scoreboard project (tx's to Mr Gibbs)), I decided to hook it up and have a really nice (strong) magnet to play with.
Only thing I knew about it was that it's resistance was 120 ohms, had no idea what the voltage requirement was.
I did a search on the internet and luckily found a schematic for one.
Apparently, the one I found (see attachment) just requires full wave rectification.
So, I conclude, perhaps this one is similar.
I devised a circuit and have implimented it, and, it works great, but, after about 10-15 minutes the magnet starts to get warm, and warmer.
This tells me that I am somewhat exceeding it's amperage rating.
Measuring the voltage I get 146VDC which corrolates to 1.2 amp.
Am thinking it probably uses only 1 amp, so am proposing adding a 26 ohm 50 Watt resistor
in series with the coil, that should drop the current down to 1 amp.
Then again, I'm thinking that's not a lot of drop, it'll probably require a bit more resistance to drop it down further, so that, I could let it run for considerable time without it heating up (as it does in real life situations using a retail drill, etc)
Any observations and opinions would be appreciated.
Am fully aware of the danger messing with the "mains" .........
I used heavy duty FBR and Cap just because I had them, etc......
Retail drill schematic didn't come out too clear but, is readable, neutral line seems to be missing on pic.......
Tx's
Oxbo