Since some of you haven't read what all TeamTekin has posted, here's some excerpts that should lay some questions to rest:
In reference to the Mamba Max FET datasheet BrianG posted:
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Originally Posted by teamtekin
Since it appears you will tear it apart and look anyway maybe I should tell you what our fet is? I think the spec sheet will impress you. Far better than what you are looking at currently for large scale applications.
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Again in reference to comparing their FET's to the MM FET's:
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Originally Posted by teamtekin
Need to protect ourselves a little. The others will find this fet also I am sure. I will tell you the continuous drain current is higher, Rds on is lower, gate charge is lower and pulse current is unbelievable. Try over 250A vs 106A. Spendy little buggers however.
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Referencing the number of FET's and heatsinking:
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Originally Posted by teamtekin
Part of the of the magic is that we use 2 boards, half the current in each one. Shhhh Super heavy copper, multi layer, designed to reduce all trace lengths.
R1 has 24 fets, R1 rpo has 48 fets. We thought the Mt would need even more, but these fets are proving to be pretty amazing. It also helps to have the high voltages. Voltage is our friend and current is a beotch. Power =VI and more V reduces the I for a given power level.
Also our solder post make really good heatsinks because they are soldered to the power planes. It is basically a copper block and we can pull the heat from anywhere. We will likely flip it over and heatsink it on top just to make sure we have lots of head room. It really is a big block of copper and we can pull heat from the entire mass.
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In reference to the BEC:
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Originally Posted by teamtekin
We are just starting to test with the larger voltages. 5s should not be a problem, but like all speedos you will need a seperate BEC. Darn hard to step down that much voltage and be able to supply any current.
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In reference to 6S operation:
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Originally Posted by teamtekin
Pretty much everyone is using 30v fets. 6s is getting pretty close and does not leave much headroom for voltage spikes. Some fets handle over voltage better than others. The manufacturers do not address areas beyond the specs so you just have to test them and see. So far these fets are incredible. The better the circuit the lower the spikes and the better the chances, but braking battery regen can still be an issue. If the battery is full and will not accept the regen charge, the voltage can go really high, really fast. Just like motor flyback current that needs a diode or a rectification circuit like our G11, if you do not give the current somewhere to go then voltage spikes can be off the map.
We will know shortly. I am pretty excited about this market and with everything else finishing up we have time now to look at some new challenges.
IF you really need 6s or more and this will not handle it, we will build one that does. That is why we are here learning.
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