Capacitors. Acceptable add ons.
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Capacitors. Acceptable add ons.
Tore apart a couple of cheapo florescent light fixtures and came across these in the electronic ballasts.
Would they be acceptable to add to the cap bank on an ESC? It is marked in Joules and not micro fared. If I understand correctly, it takes 1000 MF to make a Joule and 1000 Joules to make a fared? Then this thing is almost halfway to a 1 fared cap? Positive and negative sides are not marked....does it matter?
Would they be acceptable to add to the cap bank on an ESC? It is marked in Joules and not micro fared. If I understand correctly, it takes 1000 MF to make a Joule and 1000 Joules to make a fared? Then this thing is almost halfway to a 1 fared cap? Positive and negative sides are not marked....does it matter?
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A Joule is one amp through one ohm for one second, and is a measure of energy. It is implied that one volt is involved. There is no direct correlation between the Joule rating of a capacitor intended for use at mains voltage (whatever that might be, depending where in the world you are) and its value in Farads. Except that it will be a high voltage device, so, for its size, a low Farad value. Since it is for use on something running on AC, the lack of polarization information indicates either a non electrolytic type (even lower Farad vale) or a non-polarized electrolytic, something I can't recall running across in real life in the last 40-odd years.
Good news, probably won't do any harm. Bad news, probably won't do any good, either. Medium news, extra weight for no discernible good, unnecessary soldering where its not needed.
I am not really into the speed scene, this just caught my eye in passing.
Good news, probably won't do any harm. Bad news, probably won't do any good, either. Medium news, extra weight for no discernible good, unnecessary soldering where its not needed.
I am not really into the speed scene, this just caught my eye in passing.
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A Joule is one amp through one ohm for one second, and is a measure of energy. It is implied that one volt is involved. There is no direct correlation between the Joule rating of a capacitor intended for use at mains voltage (whatever that might be, depending where in the world you are) and its value in Farads. Except that it will be a high voltage device, so, for its size, a low Farad value. Since it is for use on something running on AC, the lack of polarization information indicates either a non electrolytic type (even lower Farad vale) or a non-polarized electrolytic, something I can't recall running across in real life in the last 40-odd years.
Good news, probably won't do any harm. Bad news, probably won't do any good, either. Medium news, extra weight for no discernible good, unnecessary soldering where its not needed.
I am not really into the speed scene, this just caught my eye in passing.
Good news, probably won't do any harm. Bad news, probably won't do any good, either. Medium news, extra weight for no discernible good, unnecessary soldering where its not needed.
I am not really into the speed scene, this just caught my eye in passing.
Would it be acceptable to add a cap bank to esc? YES , IT WOULD HELP KEEP THE ESC COOL. Just add 2 caps of the same size you already have on. The other portion of your post is answered by the gentleman from U.K. Also take the heat shrink off and see if cooling plate is hitting all the fets and if not, sand the fets level till all touch the cooling plate, When done, use Artic ice jn small portions to each fet and put new heat shrink on with heat. I did this with my T-120 esc and keeps the esc cool! BTW- I had a esc with 1000 caps and replaced the 2- 1000 caps with smaller caps and made sure the total of smaller caps equaled or within 10% of the 2-1000. Reason for changing is smaller caps cooled faster due to smaller caps size and capacity.
I found Arctic Silver paste, is that the same stuff as you said? I can't find it.
What size heat shrink you use and where you get it? HK? I have some 50mm, but I think that may be too big.
Can one increase the total Uf rating? Say it's 1000, can I increase to 2000, or 4000? Would that help protect the system if I used a small c rated battery?
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The main purpose of a heat sink is to take temperature away from the source (the power FETs) and transfer it to air. To do this effectively, as noted above, the biggest possible contact area between FET and sink is needed. To maximize conduction, the sink needs to be thick here, but needs a large surface area to get rid of the heat. Having too much bulk can be counter productive - it might well store heat and give it back when it isn't wanted, keeping the FET warmer than it really wants to be. I assume that the heat sink is in free flowing air, if its inside a box, all it is doing is heating the air inside the box, the hot air needs to have an escape path and cool air needs a way in.
I would just regard increased cooling as a way of increasing the safety margin, but then, I don't look for ultimate performance.
As an ex-wire bender, I tend to regard warm capacitors with fear. If it's getting warm, it's overworking. When they pop, the stuff that comes out smells horrible and the mess seems everlasting. A bank of smaller ones of the same total or more should be better - you get more outside surface area, good for cooling, provided the air is cooler than the surface, and, due to the internal construction, self inductance is reduced. The resulting bank can also be a more convenient shape.
Capacitors like this are there to smooth out the current fluctuations in the power leads to keep the voltage presented to the ESC as stable as possible under load. I can't see it helping a battery that has a C rating too low for the load, the overall load would still be too high for reliability.
I would just regard increased cooling as a way of increasing the safety margin, but then, I don't look for ultimate performance.
As an ex-wire bender, I tend to regard warm capacitors with fear. If it's getting warm, it's overworking. When they pop, the stuff that comes out smells horrible and the mess seems everlasting. A bank of smaller ones of the same total or more should be better - you get more outside surface area, good for cooling, provided the air is cooler than the surface, and, due to the internal construction, self inductance is reduced. The resulting bank can also be a more convenient shape.
Capacitors like this are there to smooth out the current fluctuations in the power leads to keep the voltage presented to the ESC as stable as possible under load. I can't see it helping a battery that has a C rating too low for the load, the overall load would still be too high for reliability.