Csecrist3 said:
You have a lot of great insight and didn't realize the different combinations one could have for a simple key switch!
There's more than what I listed...but you're unlikely to use any of those.
What I would like to do is have 2 positions for the key switch, on and off only. When it is on, the lights and accessories would be turned on, precharge would start to happen. Then I would like the kill switch to turn the precharge off and have power running to the motor as it's good to go. That way I can have the accessories on, but no power to the motor. In doing this setup, I would then have to still have the key switch in series with the kill switch, but have the kill switch after the key switch to allow this to happen. Would I need relays to consider this and could you map out a small drawing of what it may look like by chance? If I'm not mistaken, a pin from the contactor would be triggered by the kill switch is this correct?
I can make a (really bad
) drawing later, but first want to work out how you need it to work:
So IIUC, the very basic logic you want is:
If KYSW = ON and KYSW = OFF, then Precharge = ON and DC-DC = ON and CONTACTOR = OFF.
If KLSW and KYSW = ON, then Precharge = OFF and DC-DC = ON and CONTACTOR = ON.
Presuming the kill switch is just a simple on/off switch, and some other assumptions, here's some thoughts.
If you don't have an absolute requirement to actually turn off Precharge (because you don't really need to, exactly, though there may be good reasons to do it in some cases), then it simplifies things.
Keyswitch should probably only control a relay, and not directly control any "power", so that it can be a minimal current, which will save wear and tear on it's contacts (and might be a cheaper switch). They make "automotive" style 48v (etc) relays, that just plug into a socket, so that if it ever fails you can just pop it out and replace it. Like these:
https://endless-sphere.com/forums/download/file.php?id=288864
or other similar types. If you don't want to use a relay, it will still basically work the same way, except the stuff that would connect to the relay output would instead connect to the switch.
Assuming a relay is used, we'll give some names to things to save typing.
I dont' define any negative connections, as those are assumed to all be connected together all the time.
KYSW = keyswitch
KLSW = killswitch
CT = contactor main pins
CTC = contactor coil pins
KYSWRNO = the Normally Open (open when relay is off) contacts of the keyswitch relay
KYSWRCOM= the common pin of the keyswitch relay
KYSWRC = keyswitch relay coil pins
B+ = battery positive (or rather, the "bike side" of whatever fuse or circuit breaker you have on the battery positive).
CONT+ = controller battery positive terminal
12V+ = DC-DC 12V positive output. (or the bike side of a fuse)
12VBAT+ = DC-DC battery input
KYSW connects on one side to B+, and the other to one of the KYSWRC pins, so when it is on, it turns on the relay.
12VBAT+ connects to KYSWRNO, so it gets powered and DC-DC turns on when key is turned on. Anything powered by 12v is now turned on unless it has it's own switch.
KYSWRCOM connects to B+.
Precharge resistor is wired from KYSWRNO to the controller side of CT. So whenever contactor is not active, but KYSW is on, precharge provides it's small current to the controller, allowing precharge of the capacitors in it (to prevent damage to contactor contacts). Whenever contactor *is* active, it shorts across precharge resistor, effectively cutting it out of the circuit.
KLSW connects on one side to 12V+ and the other to one side of CTC. (so when it is active, and 12v is available, it turns on the contactor, which then provides power to the controller/motor).
I think that is all the stuff, but you'll have to go over it and tell me if i missed something (brain sez itz naptime).