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Minky

Questions on the Mosfet Master Race

Firstly apologies for all the questions, as I proceed with my build I get more and more!

Quick scene setting: Modulus mod, will be running Hellcats on 2S or 3S dependant on muzzle velocity and comp rules, was going to replace grip for more space for switch upgrade and comfort.

If I read the descriptions of the looms and what mosfets do correctly I see you can retain the original switches on the original wire is this actually preferable? Or can we get improvement by better standards of wires/switches on that circuit?

Is there any implications to running an LED lighting/ voltmeter loom (or 2) from the same power supply/off the same circuit?

Is there any implications to changing the power pack between 2S and 3S on these circuits?
Franksie

You can use the original wiring but (to me) the benefit of doing a full rewire is you can bypass the electrical locks e.g. Jam door.  Use 18 AWG for the low current circuit and 16 AWG for the high current circuit.

With regards to voltmeter you can connect the negative between the battery and the source pin and I usually wire the positive to the positive terminal of the Rev trigger.  If you don't want to have the voltmeter permanently on you can route via the jam door switch
Boff

So the gate pin of a MOSFET will only pull tiny amounts of current meaning you can leave the original switch gear in place and let the FET do the heavy lifting with 16AWG or 18AWG attached only there. That line is only there to provide a low current signal in the form of a voltage change. You won't get any performance gain from including thicker wire given that the FET's response time is already measured in nanoseconds. All this makes it far, far easier to upgrade since you're not having to change any of the wiring in the trigger cluster nor having to grind out space for a larger switch to sit in. You can by pass all the other locks by soldering around them with low current wire or leave them in if that's what you prefer.

The MOSFETs in our kits are blind to input voltage (provided you stay between 5V and 20V) so there's no difference to them between 2S and 3S. Only your motors care about voltage from a performance perspective.

Franksie is correct about routing voltmeters. I usually wire mine up to the jam door for the same reason. Your LiPos will be drawing so much current that if you wire the meters or LED looms in parallel properly then they won't bat an eyelid. Think that your LEDs are going to draw around 20mA each (0.02A) compared to Hellcats which pull 22A each at stall. If your LiPo is struggling with 20mA, you've got bigger problems! Very Happy
Minky

That's brill. Thanks so much for your replies.

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