Flip Flopping Cobs

grouch

Well-Known Member
And chips run fifty or sixty bux apiece, and you'll need double the number this way.

There has to be a better option...
The chips I'm looking at run $40 each. If it will work I can upgrade to a four cob unit for about $100 as opposed to spending $250 to replicate what I have now.
 

grouch

Well-Known Member
You can do it with a simple relay that flip flops between two outputs from a single input. You can attach the positive on the single side and flip between the two leds. If you need more explaining I can. You would need a few other things to run it.

I would use this cheap relay http://www.ebay.com/itm/Durable-10Pcs-DC5V-Contact-current-10A-5Pin-Power-Relay-for-T73-5V-SRD-5VDC-SL-C-/271890586769?hash=item3f4df11c91
Would i only swap the positive wires or would I need a relay that could swap positive and negative wires from the led?
 

bicit

Well-Known Member
Why is that? Would that damage the led or the driver?
It could potentially damage something. Though I imagine the risk is rather low. The idea of hot swapping a high voltage line like that doesn't really jive with me though. YMMV.

Would i only swap the positive wires or would I need a relay that could swap positive and negative wires from the led?
You would need to swap both sets of wires using a DPDT(double pole, double throw) relay. At least that would be the easiest method IMO.
 

grouch

Well-Known Member
With one cob per driver the voltage isn't very high. As long as the relay is rated for the voltage and amperage would there be risk? What could potentially cause the damage? Would it be the change in voltage from hot cob to cold cob?
 

bicit

Well-Known Member
With one cob per driver the voltage isn't very high. As long as the relay is rated for the voltage and amperage would there be risk? What could potentially cause the damage? Would it be the change in voltage from hot cob to cold cob?
Essentially, yes. It's your call, your equipment. personally, I like redundancy when it's affordable and easy. YMMV.
 

nevergoodenuf

Well-Known Member
If you could make something similar to the switch I a headlight, that when turned on and off quickly switches between different lights. Every 12 hours a timer could turn off the system and back on switching on the other room. I wish I knew electronics. All your lights would have to be designed for that and the rooms would need to be well thought out, but would be cool.
 

grouch

Well-Known Member
Essentially, yes. It's your call, your equipment. personally, I like redundancy when it's affordable and easy. YMMV.
So what would be the danger of doing so with a constant current driver that automatically adjusts voltage? I guess I'm not understanding where your fear is coming from. If it can adjust the voltage as the cob warms up why wouldn't it be able to do so as the other cob came online? I would really like to be able to use the equipment I have during time it's not being utilized if it's safe to do so.
 

4ftRoots

Well-Known Member
Would i only swap the positive wires or would I need a relay that could swap positive and negative wires from the led?
You could swap only the positive wires since the voltage on the ground side should be 0v. If you want to be safe you could switch the positive and negative and turn off the relay if you want. All it would require is 3 relays designed to handle the voltage and a simple Arduino sketch with a transistor handling 5 volts.

I do like the idea of turning off the driver so it does not suddenly open circuit and ramp up its voltage then hit the next cob starting at a high voltage.

The only problem with multiple relays is they will all use power when flipped.

I like 2 relays. 1 to control the driver power and 1 to swap the positive voltage. The cobs always being grounded would protect them if the relay failed.
 
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