2 drivers 1 cob

[SupraSPL]

I have never seen the famous viral video, luckily, I learned that lesson by looking at Rotten.com when the internet first came out.

Anyway, I retrofitted a pole lamp with a Vero 10 2700K in the living room and ran it at 150mA (5W). It is nice but my wife needs more light sometimes. So I got a 300mA driver and bought a 3 way switch with the intention of switching between drivers. But on the third setting this particular switch powers both drivers. I was surprised that it worked. So low is 5W (150mA), medium is 10W (300mA) and high combines both 15W (450mA).


Not sure how this could come in handy for grow lamps yet, but those 150mA drivers are only $1.25 and the switch is $3 at Walmart.

 

[bicit]

That's pretty nifty. I didn't know you could do that.

 

[churchhaze]

Current sources add in parallel and voltage sources add in series.

Sometimes with switch mode supplies, the manufacturer will tell you to avoid series/parallel combinations due to how they sense current/voltage feedback for determining switch duty cycle, but ideal power supplies have no issue adding together.

You can also put 2 voltage supplies in parallel or 2 current supplies in series, but the output voltage/current of each sink must be the same or you will have unpredictable results. (well, it will be bad)

If you add two 12V voltage supplies in parallel, you will get a 12V supply that can handle the current of the combined currents before overloading. (You lower the output impedance)

If you add two 1A current supplies in series, you will get a 1A current supply that can handle the combined output voltage.

 

[churchhaze]

I haven't checked with mean well drivers in particular, but one application of this could be to boost those 143V@1400mA drivers by putting a 5V@1400mA in series... to get that 4th vero in the string....

I think my solution to that problem will be to sell the 143V@1400mA driver and to a 1050mA version one.

 

[bicit]

Would this be safe to run for long periods? Or is it a fire hazard waiting to happen?

 

[SupraSPL]

I have let it run like that for hours and no trouble so far.

 

[Voidling]

Would be a way to do a "dimmer" without a dimmer to switch between veg and flower.

Where did you get the pole light and how much are the 300mA drivers?

 

[SupraSPL]

Just a standard pole lamp designed for a fluoro screw in E27. The 300mA driver is this one, sold out and overpriced anyway. This one should work well (8-12X1W).

 

[Voidling]

If it wasn't for wanting ceiling fans I'd be building my own light fixtures for my house

 

[Voidling]

I kind of like the look of exposed heat sinks as an industrial look. Hang one like a chandelier. Only issue is hiding the wires and the led doesn't look that good when turned off.

Concrete floors, heatsink lights, and wood ceiling. I'll never be able to sell a house with my taste in decoration

 

[SupraSPL]

I have been experimenting with it a lot and generally speaking, LED downlighting is harsh on the eyes. Lots of sharp edged shadows and if you have glasses the overhead light creates glare in the lenses. Also you get the the "pin prick" effect that can be annoying to the human eye even from a distance. So instead I have been bouncing the light off a white ceiling and it creates a much nicer light. Reduces shadows and eye strain, no "pin prick" effect. Another advantage to uplighting, it is easier to make it look aesthetic.

 

[Voidling]

I haven't been using it enough to know of this pinprick thing. Just another thing for me to experiment with

 

[bicit]

I've been looking at using led strips along the boarders of the room to create indirect ambient lighting recessed into molding. It's a nice look, but my concern has been the thermal package. I'm thinking about the rigid bars rather than the flexible tapes.

My concern with high power LED's for human lighting applications has been looking at the emitter directly. It's not good on the eyes, even at low power levels. Some sort of lens or diffuser would be necessary if you wanted to do direct lighting.

 

[Voidling]

Yeah I was just pondering heat dissipation if the heat sink is touching wood

 

[FranJan]

Just for the record, I've been running 2 drivers connected in parallel and connected to 4 COBs running in series for around 8 or so hours and it's running great. The larger of the two drivers are a tad warm and the smaller one is cool and I'm wondering if it's even working at this point since the XNovas are running real cool it seems and might be drawing just under their min fV of 32.5 volts which puts them within the voltage range of the larger driver.

So what's the drawback of running drivers like this? I never get any sleep when I introduce new lights into my grow room and I keep waiting for this setup to burst into flames so I'm getting even less sleep but it appears to be rock solid and now I'm thinking of rewiring my Veros this way. Just remote everything and have one or two wires per light running in my tent. Fuck I can move all the timers out of the grow tent too. This is turning out to be a cool little lesson, Thanx Church and Supra. Now excuse me as I put my asbestos pajamas on and try to take a nap.

And Voidling put some clothes on for Chrisakes!

 

[ballist]

With constant voltage drivers you get problems with the output voltage not being exactly the same so 1 psu with supply more of the load when run in parallel. In series you need to make sure both supplies can handle the series current. Currets add in parallel.

 

[Voidling]

I'm confused, was I posting nude photos in my sleep again? Sorry about that

 

[randomlygrow]

This seems a really cool way to get a cheap 3 stage sloppy dimmer?

CXA3070
350mA Driver & 700mA Driver in parallel or singularly. GIves you the 350,700,1050 choices we most likely use and cheap!? Debating...

Or 700mA & 1050mA driver?

 

[FranJan]

I'm confused, was I posting nude photos in my sleep again? Sorry about that

LOL Actually my bad. I couldn't see your avatar because it's sooo dark on my monitor I thought it wasn't there and I'd just bust your horns. Guess it's time to fix the gamma on my monitor or is this all macular degeneration from all these exposed LEDs I blind myself with. Anyway don't mind me V .

And I guess one reason one shouldn't wire 2+ drivers together is if one fails it would force the other drivers to try to pick up the slack and I suppose stress them out to the point of failure or at least lower life expectancy. But another plus would be it's very easy if a bit costly to build a redundant power system into your rig by doubling up the drivers.

 

[bicit]

Found an interesting article relevant to this topic.