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Old 10-30-2021, 03:43 PM   #9
Dannyx
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Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
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Posts: 3,248
Default Re: Master power switch for E-bike ideas

Actually, a mechanical switch approach may be attainable after all. I may have overestimated the currents involved, which albeit high, are manageable even with mechanical switches/relays, especially since I'd use an inrush limiter to lower it even further upon startup so it's within the rating of the contacts.

Looking through a list of relays, I'm not entirely sure how to interpret their DC ratings. Some will say something like "max 20A/400vDC Resistive"....can we assume that if it handles 20A at 400vDC it SHOULD handle 20A at 48v as well ? True, in my case, it'd be a capacitive load and the contacts would still go *BANG* if the caps are discharged. To mitigate this, I'd have it so the NC connection is wired through a resistor (small lightbulb maybe ?) to charge the caps and THEN have it switch over via a time-delay to the NO connection for the the "ON" state...that's the theory at least....
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