CMB16D injection

[Gonkulor]

Hello all.

I think I may have an unusual request. I need to know if I can supply powers and grounds to a couple of my lights via direct switching while the wires are still connected to the + and - of the board.

Explanation: I am that golf cart guy, some of you may have come across in other forums, and I have installed smart pixels throughout my golf cart. I purchased this LOR board specifically, but not solely, to power my headlights. The headlights are specialty made 18SMT LED H4 headlight bulbs. Each one runs just over 1A at full power. What I am needing is the ability to operate my headlights via a toggle switch without starting up the onboard computer and running software. I still want the lights hooked up to the LOR board so I can have blinky and flashy for sequences, but just the simple ability to turn the lights on thru a switch would be great.

I do not have the lights hooked up to the board yet. I have tested them with the board and all works as advertised. I should add, I plan to also use the LOR board to operate relays, a smoke machine and maybe a few other transistorized circuits. So don't think I bought the board just for headlights. Heheheh

If anyone can assist me? I would sure appreciate it. Maybe I can just toss a couple zener diodes into the wires on the boards side of the wiring? I'm pretty handy with electricity, common household 110 stuff tickles but my cart packs 800amps + so I'm reluctant to "play" as is.

Best Regards

Shon

[Max-Paul]

Ok, you have the positive lead to the lights on one side of the lights. And the wire comes back out the other side of the light going to the controller negative post of that channel. In short the controller is switching the negative to the light. I can not see any reason why you cant install a switch between the negative terminal of the channel and to the negative of the battery. This switch would effectively be in parallel with the MOSFET transistor of the controller.

[Gonkulor]

Max ty for the reply. If I understand electrons properly they are like a waterpipe. Your saying I can share the ground. My fear is spreading 12v DC to the light and it feeding back to the board. I am good with electricity but not when it gets into mosfets, diodes and crap.

If my fears are ungrounded I could add a zener diode to the power supply and all should be good. I'm fearing the voltage coming back to the board and it the board is not on a common ground. I fear the ground also goes thru the mosfet. That would mean I'm pushing a lot of power to something not ready to handle it.

bah, that last didn't make sense... grr.

[Steven]

It's backwards from what you are thinking. The MOSFETs act like a switch between the negative (-) terminal of the channel and the negative (-) power supply input, not the positive.

All positive (+) channel terminals go directly to the positive power supply input. (Channels 1-8 go to one and channels 9-16 go to the other). The negative power supply terminals are common between the 2 power supply inputs.

Will you be using your golf cart battery to power the CMB-16D? If so, then no problem. Hook up your headlight bypass switch between the negative lead of your headlights and ground. Note that when hooked up to the powered CMB-16D, there will be a constant +12V present on the positive lead of the headlights, even when they are off.

[Gonkulor]

Appreciate the added comment Steven. You explaining the Neg side of the situation really helps comfort me greatly. I'll pick up a DPST switch. That should make the situation work as advertised.

I don't have all the electrical juice coming from the carts primary pack but a 36v to 12v converter tapped of a secondary 36v pack. Regardless, it's the same thought and the ground will be a true common vs having the neg supply from a different battery pack.

I'm excited to get this LOR board up and running in my system. This board is a great asset and will power so much more stuff to.

I appreciate everyone's comments. God bless.

Shon

[Max-Paul]

Whoa, Wait a minute. You just threw in a new equation. Using a DC to DC converter might change things a bit. Once your on the down side of the converter. Everything has to stay on the down side. I would not allow anything that you call negative cross over from the 12v side mix with the negative of the 36v side. Not knowing how the converter is built and its requirements.

[Gonkulor]

OK. But I can fix that. I can use the converter to power the lights in either circumstance. Unless I configure the batteries properly. I have 3 12v deep cycle batteries. The last battery in the series connected might be ok. It would be safer for me no just run the lights off of the 500watt converter used to run the LOR board regardless. It's kind of a think about differential potential if I use the converter and straight of the batteries. It wouldn't take any more effort to run everything of the converter, only takes me flipping an axtra switch.

Back to powering the lights. I have one more question. Even thought at this time I use one toggle switch to power them and they are paralleled in a circuit of the battery but I want the LOR board to control them individually. Should I go to a DPDT switch?

This is turning out to be more of an obstacle than I had originally thought.

[-klb-]

One thing in your favor is that golf carts are not wired like cars. The frames are floating, not a ground. As long as you keep the negative output from the DC to DC converter separated from your 36V grounds you should be fine. In many cases, you would probably be fine even if they were combined, depending on how the converter is designed.

I would probably use a DPDT center off switch, so you could select on/off/sequenced. I don't think you will have any issues at all wiring this, or making it work as you want.