Post #2298957
2026-04-14 11:37 UTC
@LeoDJ@chaos.social I felt my butt clench a bit while reading 48V/500A. That's some serious current. Not sure I understand it correctly though - Is that full 500A current running through Q1 and Q2, or is that big tube thingy the contactor, and Q1 and Q2 are just required to provide enough switching juice for the contactor? I'm totally out of my depths here, but the labelling around Q1 and Q2 suggested to me that all of the current flows through them. And the PCB traces do not look 500A capable to me :D
Replies (1)
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@LeoDJ@chaos.social 2026-04-14 12:19
@thunfisch@chaos.social Ye, that big tube thingy is the contactor. A Gigavac GV200, 500A 800V DC contactor to be exact. It will conduct the main current between battery + and motor controller +. But because motor controllers have quite beefy and low ESR input capacitors, if the contactor would simply make the connection when the input caps are empty, there would be many kiloamps flowing through not-quite-mated switch contacts, trying to charge the caps rapidly.