another mars 300 to cob - question

Halfandhalf

Well-Known Member
I have 3 vero 29 version D's that I hooked up to an old mars 300 with two drivers inside. They read 55-100v for one, shared with a fan, and 55-86V for the other one, both at .65A. I hooked up two of the cobs to the one shared with the fan and they run fine. I however hooked up the other one to the 55-86V driver and it too runs fine as far as I can see. But it would have to be running below the minimum voltage, so what's actually happening? I haven't hooked up a voltmeter to it yet (my voltmeter has a blown fuse I need to replace) so I don't know what it's actually running at but it looks the same as the others. What is likely to happen? Will I blow out my cob? Will the driver die? Is it fine? I only ran it for 30 seconds.

From the vero sim, at that amperage the cob should be running at 33.6V.
 

Nugachino

Well-Known Member
Does it flicker at low voltage? Because my cobs do that with the dimmer set to the lowest third of their settings.
 

Halfandhalf

Well-Known Member
No flickering. It flickered when I hooked up all 3 to one... Dimmers should be affecting amperage anyway afaik.
 

Nugachino

Well-Known Member
Well hopefully someone with more experience comes along. I don't think under voltage will hurt them. Not like over voltage.
 

Halfandhalf

Well-Known Member
Hope someone can help but just to be clear the cob isn't under volted, the driver is. Or the cob is overvolted, not really sure. One of those two..
 

iHearAll

Well-Known Member
The voltage is 38.7v according to my google search. So three of these is past your driver's 86v peak. So, look at it like 86÷3=28.7v across each vero29. According to the charactarstic curve on the data, the vero29 won't light up at that voltage.
Capture+_2017-07-05-09-56-57.png
 

Halfandhalf

Well-Known Member
The voltage is 38.7v according to my google search. So three of these is past your driver's 86v peak. So, look at it like 86÷3=28.7v across each vero29. According to the charactarstic curve on the data, the vero29 won't light up at that voltage.
View attachment 3972721
Did you even read my post? It did light up. It does run at 33.6v at that amperage, it's two drivers. No offense but why even bother replying if you aren't gonna read it?
 

iHearAll

Well-Known Member
Did you even read my post? It did light up. It does run at 33.6v at that amperage, it's two drivers. No offense but why even bother replying if you aren't gonna read it?
Spare me, I misread it.. I thought you were saying you plugged together your three chips and it didnt light up. Regardless, the manufacturer has a specified window they can gauruntee accuracy of a constant current , below this is a balance of power handling in the chip and above this is limited by the driver. Buy another chip and you'll guarunteed be ok. I would not leave the driver on for hours a day if you are out of the operating range by 20v. Pull up the datasheet to clarify this because it could be fine. I apologize for not reading correctly
 

Halfandhalf

Well-Known Member
Spare me, I misread it.. I thought you were saying you plugged together your three chips and it didnt light up. Regardless, the manufacturer has a specified window they can gauruntee accuracy of a constant current , below this is a balance of power handling in the chip and above this is limited by the driver. Buy another chip and you'll guaranteed be ok. I would not leave the driver on for hours a day if you are out of the operating range by 20v. Pull up the datasheet to clarify this because it could be fine. I apologize for not reading correctly
Thanks for the reply, I'm a bit on edge today so I apologize for that.

Adding another chip means I have to get another heatsink and at that point I might as well spring for a new driver. I might just run this and see what happens. Worst case i lose one driver and one cob. Got these for 50% off anyway.
 

iHearAll

Well-Known Member
Thanks for the reply, I'm a bit on edge today so I apologize for that.

Adding another chip means I have to get another heatsink and at that point I might as well spring for a new driver. I might just run this and see what happens. Worst case i lose one driver and one cob. Got these for 50% off anyway.
Same Lol my bad
 

Growcob5

Active Member
I have 3 vero 29 version D's that I hooked up to an old mars 300 with two drivers inside. They read 55-100v for one, shared with a fan, and 55-86V for the other one, both at .65A. I hooked up two of the cobs to the one shared with the fan and they run fine. I however hooked up the other one to the 55-86V driver and it too runs fine as far as I can see. But it would have to be running below the minimum voltage, so what's actually happening? I haven't hooked up a voltmeter to it yet (my voltmeter has a blown fuse I need to replace) so I don't know what it's actually running at but it looks the same as the others. What is likely to happen? Will I blow out my cob? Will the driver die? Is it fine? I only ran it for 30 seconds.

From the vero sim, at that amperage the cob should be running at 33.6V.
If it cheap multimeter just put a piece of metal and between where the fuse goes just to get a reading
 

Growcob5

Active Member
Thanks for the reply, I'm a bit on edge today so I apologize for that.

Adding another chip means I have to get another heatsink and at
Look at this on eBay http://www.ebay.com/itm/231172876899. There's only two whoever needs a key that driver it will run one check guarantee that 50 wats go to the link look at the specification it says that it can run 10 chips and series at 34 volts :36 can run Five and parallel I don't want understand I guess when you run something in parallel it goes by the wattage in the attic and I'm assuming when you're running in series it goes by voltage that's the only thing I can in soon
 

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NoFucks2Give

Well-Known Member
Constant Current Drivers automatically adjust to the forward voltage. Replace the fuse on your voltmeter and measure it. Not likely there is anything wrong.
 
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