Can't say too much because patents are involved with the process. Switch mode power supplies where tried by someone else and didn't work. Its an electrochemical process.
I've just finished mounting 40 MOSFETs, using self tappers into 4 large fan cooled heat sinks. One worrying thing now is the heat sinks are at +/-50v and they are on the outside of the case. Looks like I'll need to construct a finger guard.
I'll double check everything on Monday before switching it on. Not doing it now, because its my Birthday at the weekend and I'd like to reach 41. The cells for the +/-200V 50A version will now be connected in parallel, so its +/-50V 200A
ecotack,
You need to take a few minutes to write down your specs and do some basic calculations. Do you realize that 50 volts at 200 amps is 10 KW? How are you going to produce the raw DC for this monster? This is not a job for an emitter follower or linear amp. You must use some kind of switch mode circuit; perhaps like a class D amplifer.
Rick
You need to take a few minutes to write down your specs and do some basic calculations. Do you realize that 50 volts at 200 amps is 10 KW? How are you going to produce the raw DC for this monster? This is not a job for an emitter follower or linear amp. You must use some kind of switch mode circuit; perhaps like a class D amplifer.
Rick
Yes, I listened to it for several weeks before delivering it. It sounds stunning but the thing is way too big to fit into anywhere. There is nothing that beats raw power. Difficult to test it though, used a roll of 1.6 sq mm copper wire in a bucket of water. It has been in service for two years and no complaints.
"Can't say too much because patents are involved with the process."
Well OK, and you cant say what its for, or where you are going to get the 10KW.
Be carefull my friend, this is a machine that can spit bullets! Oh, and happy birthday.
Well OK, and you cant say what its for, or where you are going to get the 10KW.
Be carefull my friend, this is a machine that can spit bullets! Oh, and happy birthday.
After a few flame outs with gate resistors (figured it didn't need them so did away with them in the end) and some oscillation on the potentiostat circuit, it has managed to push -45A and only gets a little warm. The op-amp was running out of potential to drive the MOSFETS, so its being replaced by a higher voltage one, so I can turn the voltage back up.
I'm having problems with the positive side though, there is high frequency oscillation on the N-channel MOSFETS. If you place a magnet near to the output the magnet whistles ;o)
Presumably a ferrite bead on the gate is needed, but will I then need to put the gate resistors back in? How do I chose a suitable ferrite bead and gate resistor? Or can anyone save me a bit of time and recommend ones to use?
I'm having problems with the positive side though, there is high frequency oscillation on the N-channel MOSFETS. If you place a magnet near to the output the magnet whistles ;o)
Presumably a ferrite bead on the gate is needed, but will I then need to put the gate resistors back in? How do I chose a suitable ferrite bead and gate resistor? Or can anyone save me a bit of time and recommend ones to use?
Hmm, sounds like something is not completely correct.
Smoke and flame-outs are never a good thing in electronics and especially with solid state.
I can almost assure you oscillation will take place if you have no filter to dampen the reactive components that make up a Mosfet. If the load is highly reactive you may need to further derate the transistors.
Yes, something wasn't completely correct, namely the wattage of the resistors I used.
I'll try the gate resistors again, but this time use some 2.5 watt ones.
I'll try the gate resistors again, but this time use some 2.5 watt ones.
why?
The gate stopper does not pass DC current.
It only passes AC current to charge and discharge the gate pin.
Look at the FQA Fairchild mosfets.
Some of these have huge current reserves; for example the FQA36N15 is rated to 36A continuous, 144A surge, 19S, with up to 150V rating.
Hugh
Some of these have huge current reserves; for example the FQA36N15 is rated to 36A continuous, 144A surge, 19S, with up to 150V rating.
Hugh
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