For my first thread, an extreem mot power supply !
Vigh holtage, Sat Dec 09 2017, 01:55AMOk guys this is my first thread here but no stranger to you tube, anyway i built a huge 4 pack mot power supply all self contained in a big mark 19 grenade launcher ammo can !
I am looking for some help basically judge it and let me know what you think and if i am on the right track with balasting .
Any help on a suitable balast that will handle 4 kva or more and not over heat ? I thought of 2in pvc filled with an iron bars and wrapped in 250ft 12g wire or even 2 mot E cores and 4 primary windings ?
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Sat Dec 09 2017, 02:03AM
Ok here are the videos on my youtube channel explaining everything and drawing arcs!!!
Vigh holtage, Sat Dec 09 2017, 02:03AM
Ok here are the videos on my youtube channel explaining everything and drawing arcs!!!
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Sat Dec 09 2017, 02:28AM
Here is the begining of the build, i may run it balasted at 15-20 amps and full wave rectified to 13,000 vdc into a smoothing bank then 4 to 5 charging chokes of around 5 henry each with decoupling diodes and an asynchronous rotary gap.
End result should be around 26,000 volts into the tank capasitor !!!!!
Vigh holtage, Sat Dec 09 2017, 02:28AM
Here is the begining of the build, i may run it balasted at 15-20 amps and full wave rectified to 13,000 vdc into a smoothing bank then 4 to 5 charging chokes of around 5 henry each with decoupling diodes and an asynchronous rotary gap.
End result should be around 26,000 volts into the tank capasitor !!!!!
Re: For my first thread, an extreem mot power supply !
profdc9, Sat Dec 09 2017, 11:52PM
A higher voltage primary may not necessarily be better. I built a switching power supply for my Tesla coil that produced 30+ kV and it was very difficult to prevent the RF spikes from feeding back into my transformer and destroying it. Preventing arcing from primary to secondary was also more difficult as well. I was using a custom ferrite transformer, but any diodes in your voltage doubler might be damaged by RF spikes. Something to consider. Each of the MOVs I used is rated from 1.4 kVDC, so you'll need 20 or more of them in series to absorb the RF spikes, as well as a very high voltage cap bank for a Terry filter if you decide to use one. You will also need higher voltage primary capacitors, but a lower capacitance, and a higher impedance primary in general, so you will end up getting the same voltage on the secondary anyways. There may be less spark gap loss though with the smaller current with the higher voltage, but it seems to me once one has 10 kV or more, the spark gap can fire fairly reliably and higher voltage is probably not going to help that much.
Dan
profdc9, Sat Dec 09 2017, 11:52PM
A higher voltage primary may not necessarily be better. I built a switching power supply for my Tesla coil that produced 30+ kV and it was very difficult to prevent the RF spikes from feeding back into my transformer and destroying it. Preventing arcing from primary to secondary was also more difficult as well. I was using a custom ferrite transformer, but any diodes in your voltage doubler might be damaged by RF spikes. Something to consider. Each of the MOVs I used is rated from 1.4 kVDC, so you'll need 20 or more of them in series to absorb the RF spikes, as well as a very high voltage cap bank for a Terry filter if you decide to use one. You will also need higher voltage primary capacitors, but a lower capacitance, and a higher impedance primary in general, so you will end up getting the same voltage on the secondary anyways. There may be less spark gap loss though with the smaller current with the higher voltage, but it seems to me once one has 10 kV or more, the spark gap can fire fairly reliably and higher voltage is probably not going to help that much.
Dan
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Sun Dec 10 2017, 01:14AM
Ok so i suspected as much anything over 20 KV is probably just too difficult to insulate and deal with.
I have (10) 20kv 2a diodes, and (100) 1kv 6a fast recovery diodes FR607 's soo...
My secondary idea was to just connect a full wave rectifier to a smoothing Bank for 13.5kv ish, and run that to an asynchronous Gap but ... I am not sure how the parallel smoothing Bank before the asynchronous gap will affect the series connected tank capacitor.
I'm not sure if the Transformer will see the Gap firing into the tank cap as a short circuit.
If this doesn't work out then I can still full wave rectify it which would provide me with 13.5 KV of 120 hertz pulses which is a reasonable voltage at twice the line frequency which would allow me to still use a synchronous rotary Gap
I have (4)1/2 horsepower induction Motors from polishing machines, these run at 3450 RPMs and can be modified with just two Flats to be synchronous at 3600 and I have four to play with , along with three 1500 W vacuum motors for an asynchronous gap
Lastly i can just push the 9800 vac into a multie static spark gap if all else fails but that would mean a massively expencive maxwell 100 nf pulse cap and be difficult to quench. I only have a 20nf 45kv maxwell to play with, i could add an mmc in parrallel i guess but still cost prohibitive, (10) 12nf bucket caps in parralell mabey roflao ???
I am a machinist so i have acsess to infinity 1/4 shank tungsten bits that are dull and no longer get used, they have 2inches of perfect shank on them so i cut them to 2in and bring them home, i can machine any kind of gap nessasary for this
Aso i will be pouring the oil tomorrow to cover those mots, i am going to use generic full synthetic motor oil that has a light wieght and will be thin not thick and viscous, i may actually add mineral oil in a 1:1 ratio to make it even thinner so it can get in and between everything if nessasary.
This transformer will be painted nicley and be a permanat fixture in my lab wich is half my basement , so i want it done RIGHT form the start. 13.5 kv dc pulsed, or smoothed dc, or 9800 vac and it must be compleatly self contained in that grenade launcher ammo can, balast and all, so all i have to do is run cable to a spark gap mounted in a base with a tank cap and the coil on top, or just hook it whatever HV crap i dream up.
I do also have a 15kv 120ma nst bank with emi protection, filtering, and pfc, but that is part of a dedicated AC tesla coil i bring to the high scool for demos so i dont use it for anything else period, i cant risk frying an expencive nst bank for my hobby experimenting and then not even be able to run my demo coil as a result ! That is why i am building this supply, i can get mots at my salvag yard for 5$ a piece ! They have a huge bin full so replacing a fried mot is kiddy work, replacing a 15kv 60ma nst or 2 is out of my budget !
Vigh holtage, Sun Dec 10 2017, 01:14AM
Ok so i suspected as much anything over 20 KV is probably just too difficult to insulate and deal with.
I have (10) 20kv 2a diodes, and (100) 1kv 6a fast recovery diodes FR607 's soo...
My secondary idea was to just connect a full wave rectifier to a smoothing Bank for 13.5kv ish, and run that to an asynchronous Gap but ... I am not sure how the parallel smoothing Bank before the asynchronous gap will affect the series connected tank capacitor.
I'm not sure if the Transformer will see the Gap firing into the tank cap as a short circuit.
If this doesn't work out then I can still full wave rectify it which would provide me with 13.5 KV of 120 hertz pulses which is a reasonable voltage at twice the line frequency which would allow me to still use a synchronous rotary Gap
I have (4)1/2 horsepower induction Motors from polishing machines, these run at 3450 RPMs and can be modified with just two Flats to be synchronous at 3600 and I have four to play with , along with three 1500 W vacuum motors for an asynchronous gap
Lastly i can just push the 9800 vac into a multie static spark gap if all else fails but that would mean a massively expencive maxwell 100 nf pulse cap and be difficult to quench. I only have a 20nf 45kv maxwell to play with, i could add an mmc in parrallel i guess but still cost prohibitive, (10) 12nf bucket caps in parralell mabey roflao ???
I am a machinist so i have acsess to infinity 1/4 shank tungsten bits that are dull and no longer get used, they have 2inches of perfect shank on them so i cut them to 2in and bring them home, i can machine any kind of gap nessasary for this
Aso i will be pouring the oil tomorrow to cover those mots, i am going to use generic full synthetic motor oil that has a light wieght and will be thin not thick and viscous, i may actually add mineral oil in a 1:1 ratio to make it even thinner so it can get in and between everything if nessasary.
This transformer will be painted nicley and be a permanat fixture in my lab wich is half my basement , so i want it done RIGHT form the start. 13.5 kv dc pulsed, or smoothed dc, or 9800 vac and it must be compleatly self contained in that grenade launcher ammo can, balast and all, so all i have to do is run cable to a spark gap mounted in a base with a tank cap and the coil on top, or just hook it whatever HV crap i dream up.
I do also have a 15kv 120ma nst bank with emi protection, filtering, and pfc, but that is part of a dedicated AC tesla coil i bring to the high scool for demos so i dont use it for anything else period, i cant risk frying an expencive nst bank for my hobby experimenting and then not even be able to run my demo coil as a result ! That is why i am building this supply, i can get mots at my salvag yard for 5$ a piece ! They have a huge bin full so replacing a fried mot is kiddy work, replacing a 15kv 60ma nst or 2 is out of my budget !
Re: For my first thread, an extreem mot power supply !
profdc9, Sun Dec 10 2017, 03:03AM
I think your idea of using 4 MOTs is a good one. I am using 2 MOTs with doubler because I don't want to have to worry about arcing from the secondary of the MOT to the primary and have to cover it all in oil. That makes me a little nervous, but others seem to have done it successfully and certainly you can get a lot of power that way.
I just built a static spark gap with two tungsten rod gaps, 1/4" rod diameter. I think especially for that much power you will need an extremely strong blower to keep the gap cool and quenched. I could not get it quenched correctly and I was thinking of buying a cheap electric leaf blower to blow on the gap! Rotary gap sounds like the way to go. I have read that for very high power like pole transformers, a static gap is added in series with the rotary to help quenching as well.
For 60 Hz rectification I have used microwave oven diodes in series (4 of them) but for switching power supplies I think you need a fast 100 ns-type diode. I have used UF4007 in series and it works ok. I have two-part epoxy I bought from Amazon in a big container and I insulate using that.
Why are you using smoothing? Does it help make the arcs longer? It might make the pulse energy more even I suppose, rather than peaking in the AC cycle. You won't get the 60 Hz buzz to the arcing, which may be an advantage or disadvantage.
I do not think you can use iron bars for a high permeability core for an inductor, because the eddy current losses are too high. This is why laminated steel is used in transformer cores, because it is a high permeability but the flux loops are broken by the laminations to minimize the eddy currents.
Anyways that is nice work. Make sure the ammo can case is safety grounded!
Dan
profdc9, Sun Dec 10 2017, 03:03AM
I think your idea of using 4 MOTs is a good one. I am using 2 MOTs with doubler because I don't want to have to worry about arcing from the secondary of the MOT to the primary and have to cover it all in oil. That makes me a little nervous, but others seem to have done it successfully and certainly you can get a lot of power that way.
I just built a static spark gap with two tungsten rod gaps, 1/4" rod diameter. I think especially for that much power you will need an extremely strong blower to keep the gap cool and quenched. I could not get it quenched correctly and I was thinking of buying a cheap electric leaf blower to blow on the gap! Rotary gap sounds like the way to go. I have read that for very high power like pole transformers, a static gap is added in series with the rotary to help quenching as well.
For 60 Hz rectification I have used microwave oven diodes in series (4 of them) but for switching power supplies I think you need a fast 100 ns-type diode. I have used UF4007 in series and it works ok. I have two-part epoxy I bought from Amazon in a big container and I insulate using that.
Why are you using smoothing? Does it help make the arcs longer? It might make the pulse energy more even I suppose, rather than peaking in the AC cycle. You won't get the 60 Hz buzz to the arcing, which may be an advantage or disadvantage.
I do not think you can use iron bars for a high permeability core for an inductor, because the eddy current losses are too high. This is why laminated steel is used in transformer cores, because it is a high permeability but the flux loops are broken by the laminations to minimize the eddy currents.
Anyways that is nice work. Make sure the ammo can case is safety grounded!
Dan
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Sun Dec 10 2017, 08:27PM
Smoothing rectified mots make compleatly insane and deady powerfull blue arcs that hummmm and growl at you !
Its compleatly unnessasary for a tesla coil that uses a syncronous gap but with an asyncronous gap it will fire at any rpm because there is no space in between pulses.
I have about 4lbs of 1/4 tungsten carbide and (4) 1/2 hp induction motors i can make syncronous soo....
I want to know if i should just leave it 9800 volts ac and go multie gap / sync gap combo
Or
Rectify it and sync the motor to the unsmoothed dc pulses, ether half wave 60hz or full wave 120hz
And has anyone rectified and smoothed a tesla power supply for asyncrous operation.... i know the charging choke design stores energy as a magnetic field and acts like a smoothing cap / doubler, i dont want to use a charging choke though because i do not want to double the 13.5kv comming out, hence the smoothing cap as an energy storage device to replace the charging choke doubler.
Vigh holtage, Sun Dec 10 2017, 08:27PM
Smoothing rectified mots make compleatly insane and deady powerfull blue arcs that hummmm and growl at you !
Its compleatly unnessasary for a tesla coil that uses a syncronous gap but with an asyncronous gap it will fire at any rpm because there is no space in between pulses.
I have about 4lbs of 1/4 tungsten carbide and (4) 1/2 hp induction motors i can make syncronous soo....
I want to know if i should just leave it 9800 volts ac and go multie gap / sync gap combo
Or
Rectify it and sync the motor to the unsmoothed dc pulses, ether half wave 60hz or full wave 120hz
And has anyone rectified and smoothed a tesla power supply for asyncrous operation.... i know the charging choke design stores energy as a magnetic field and acts like a smoothing cap / doubler, i dont want to use a charging choke though because i do not want to double the 13.5kv comming out, hence the smoothing cap as an energy storage device to replace the charging choke doubler.
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Tue Dec 12 2017, 01:51AM
Here are some arcs with a 9.6 mh balast installed,
After balasting the voltage dropped from 9800 to just over 8,000 and short circuit current measured 18.5 ma at 12vac soooo 185 ma at 120vac
Vigh holtage, Tue Dec 12 2017, 01:51AM
Here are some arcs with a 9.6 mh balast installed,
After balasting the voltage dropped from 9800 to just over 8,000 and short circuit current measured 18.5 ma at 12vac soooo 185 ma at 120vac
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Sat Dec 16 2017, 01:20AM
Okay here is the capacitor bank for my voltage doubler circuit it consists of 15 microwave oven capacitors wired in a series of three and 5 strings in parallel this gives 1.5 microfarad and I can probably handle around 15 thousand volts maximum, I'm going to use the typical microwave oven doubler setup using a 20000 Volt 2 Amp diode
Vigh holtage, Sat Dec 16 2017, 01:20AM
Okay here is the capacitor bank for my voltage doubler circuit it consists of 15 microwave oven capacitors wired in a series of three and 5 strings in parallel this gives 1.5 microfarad and I can probably handle around 15 thousand volts maximum, I'm going to use the typical microwave oven doubler setup using a 20000 Volt 2 Amp diode
Re: For my first thread, an extreem mot power supply !
GrantX, Sat Dec 16 2017, 07:54AM
Is there any insulation between the metal cans of each capacitor? If they're in direct contact you might have a risk of internal flashover once the voltage is high enough. I'm not sure how much internal clearance they have around the terminals and can, it might be fine, or you might kill a whole string.
GrantX, Sat Dec 16 2017, 07:54AM
Is there any insulation between the metal cans of each capacitor? If they're in direct contact you might have a risk of internal flashover once the voltage is high enough. I'm not sure how much internal clearance they have around the terminals and can, it might be fine, or you might kill a whole string.
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Sun Dec 17 2017, 06:13PM
I dont expect them to last long lol. They are here to abuse until i can make a proper mmc for the doubler/rectifier
Vigh holtage, Sun Dec 17 2017, 06:13PM
I dont expect them to last long lol. They are here to abuse until i can make a proper mmc for the doubler/rectifier
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Wed Dec 20 2017, 10:54AM
they are under oil now, the humming noise is down a lot now except for the balast, also i have a 2 pole 20amp switch i am going to wire to the balast so i can switch it on or off and run it balasted on one pole of the switch or unbalasted off the other pole incase i want to use a differant external balast. This way i can shut off and bypass the internal balast with a flick of a switch then use it like that.
Small video.
Vigh holtage, Wed Dec 20 2017, 10:54AM
they are under oil now, the humming noise is down a lot now except for the balast, also i have a 2 pole 20amp switch i am going to wire to the balast so i can switch it on or off and run it balasted on one pole of the switch or unbalasted off the other pole incase i want to use a differant external balast. This way i can shut off and bypass the internal balast with a flick of a switch then use it like that.
Small video.
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Wed Dec 27 2017, 01:08AM
Alrighty , some more work done !
I got 2 of my 4 meters in from china the other 2 are stuck in a warehouse somewhere but i am assured that i will get them , lol ...
I installed a all in one power meter on the input of the ac power supply/variac and added a didgital volt meter to the output, just got to add my amp meter and my didgital thermometer and probe. !
Here is the video of the variac and the installed power monitering meters
Vigh holtage, Wed Dec 27 2017, 01:08AM
Alrighty , some more work done !
I got 2 of my 4 meters in from china the other 2 are stuck in a warehouse somewhere but i am assured that i will get them , lol ...
I installed a all in one power meter on the input of the ac power supply/variac and added a didgital volt meter to the output, just got to add my amp meter and my didgital thermometer and probe. !
Here is the video of the variac and the installed power monitering meters
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Thu Dec 28 2017, 10:49AM
I have run into a problem that only presented itself once the meters were installed in my 3kva variac, i had a so called utility outlet that i was using to power the heavy dutui equipment, and i saw a 20 volt drop at 20 amps !!!
Well first i checked the outlet by removing it and saw it had only 2 white wires that were 14-16 awg !!!!! Wtf and no ground at all !!! !!!
Whaaaaaat ?
Whoever wired this with all the same color white wire and sorely under sized guage wire for the breaker needs a punch to the head !!!
Soo i had to buy a single 30 amp utillity outlet and rewire the breaker box to the outlet using 10awg solid copper romex style black, white, ground.
So the breaker outlet is fixed but now but my extention cord is to thin and there is still a significant drop with 30feet of 14awg cord ! So now i got to buy 25 feet of 10awg cord and a 30amp male utility plug to make a new cord for my variac to prevent this voltage drop Aaaaahhh !
At least i fixed the breaker, it is properly wired and grounded now for 30 amps @ 120 volts.
Vigh holtage, Thu Dec 28 2017, 10:49AM
I have run into a problem that only presented itself once the meters were installed in my 3kva variac, i had a so called utility outlet that i was using to power the heavy dutui equipment, and i saw a 20 volt drop at 20 amps !!!
Well first i checked the outlet by removing it and saw it had only 2 white wires that were 14-16 awg !!!!! Wtf and no ground at all !!! !!!
Whaaaaaat ?
Whoever wired this with all the same color white wire and sorely under sized guage wire for the breaker needs a punch to the head !!!
Soo i had to buy a single 30 amp utillity outlet and rewire the breaker box to the outlet using 10awg solid copper romex style black, white, ground.
So the breaker outlet is fixed but now but my extention cord is to thin and there is still a significant drop with 30feet of 14awg cord ! So now i got to buy 25 feet of 10awg cord and a 30amp male utility plug to make a new cord for my variac to prevent this voltage drop Aaaaahhh !
At least i fixed the breaker, it is properly wired and grounded now for 30 amps @ 120 volts.
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Thu Dec 28 2017, 11:26AM
Double post
Vigh holtage, Thu Dec 28 2017, 11:26AM
Double post
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Thu Dec 28 2017, 11:26AM
Double post
Vigh holtage, Thu Dec 28 2017, 11:26AM
Double post
Re: For my first thread, an extreem mot power supply !
Vigh holtage, Thu Dec 28 2017, 11:26AM
Sorry I didn't take any pictures of the process I was kind of aggravated that what I saw and didn't think to pull up my camera but I did take an after picture of the new outlet when I get home I will add some pictures of inside the breaker
Edit... I may change it over to a larger spin lock Outlet and use it for powering only the variac which would have a very long 10 gauge cord with a male spinlock adapter depending on cost
Edit ... it appears this Outlet is only rated at 20 amps continuous so I will need a Nema L5 30 amp twist-lock outlet which I'm probably going to have to swap Breakers and simply add another receptacle besides this one and replace this breaker with a 15 or 20 amper
Ahhhhh , it's very easy to build a Mot power supply powering it sufficiently however is another story by the time I'm done I could run a pole Pig of the outlet required for this Supply !!!!!
Vigh holtage, Thu Dec 28 2017, 11:26AM
Sorry I didn't take any pictures of the process I was kind of aggravated that what I saw and didn't think to pull up my camera but I did take an after picture of the new outlet when I get home I will add some pictures of inside the breaker
Edit... I may change it over to a larger spin lock Outlet and use it for powering only the variac which would have a very long 10 gauge cord with a male spinlock adapter depending on cost
Edit ... it appears this Outlet is only rated at 20 amps continuous so I will need a Nema L5 30 amp twist-lock outlet which I'm probably going to have to swap Breakers and simply add another receptacle besides this one and replace this breaker with a 15 or 20 amper
Ahhhhh , it's very easy to build a Mot power supply powering it sufficiently however is another story by the time I'm done I could run a pole Pig of the outlet required for this Supply !!!!!
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