Adding fans to my led build
- Thread starter Geert
- Start date
I'm no expert, but I think youd want to get a cheap 24 volt driver to dive them separately. The fans will be pulling a lot less current which I believe will lead to some problems in the circuit.
Again no source of knowledge here but it seems like you could source a new driver for a few extra dollars if you wanted to add the fans.
ilovereggae
Well-Known Member
I agree 100%. if u had a CC driver it might be able to work. but not with a CV driver in parallel doesn't seem like a good match.
if the fans are 4W at 24V it's using @ 165ma of current. you would have one parallel string pulling less current than the strips at 480ma. if magically at 21V they only pull 120ma then u could have 4 in series, but that is probably wishful thinking. u would have to look at datasheets to find out.
but I would probably rather just get a 24V wall wart for $10 and be done with it.
Major Blazer
Well-Known Member
In a parallel circuit individual branch currents divvy up into separate branches and yes there can be more/less current in one branch than there is in another. That said, for varying other reasons I'd run a separate driver for your fans.
Rocket Soul
Well-Known Member
Thanks, so Its possible? I don't like to add another power plug and cable to the build if It ain't necesary
ilovereggae
Well-Known Member
thanks for this, I always assumed incorrectly that in parallel circuit each string got equal current.
Prawn Connery
Well-Known Member
In parallel circuits each circuit gets equal voltage (less voltage drop from the conductor wire) and draws whatever current it can use at that voltage.
In series circuits each circuit gets equal current, with voltage dropping through each successive circuit.
With a CV driver you can deliver equal voltage to both the strips and fans and they will each draw whatever current they need at that voltage.
The problem is if you feed the strips 24V, then they will draw much more than 480mA. But if you feed the fan 22.5V (strip max), then it will spin a bit slower and use less than 4W. That assumes you have enough voltage to spin the fan up in the first place – due to inertia, fans require more voltage to start spinning and less voltage to continue spinning.
The bottom line is I would try it first to see if you get the fan performance you require before buying a separate driver. You never know, it just might work!
In series circuits each circuit gets equal current, with voltage dropping through each successive circuit.
With a CV driver you can deliver equal voltage to both the strips and fans and they will each draw whatever current they need at that voltage.
The problem is if you feed the strips 24V, then they will draw much more than 480mA. But if you feed the fan 22.5V (strip max), then it will spin a bit slower and use less than 4W. That assumes you have enough voltage to spin the fan up in the first place – due to inertia, fans require more voltage to start spinning and less voltage to continue spinning.
The bottom line is I would try it first to see if you get the fan performance you require before buying a separate driver. You never know, it just might work!
Thanks for this good explanation, my driver is the HLG 320H-24B wich says it is CV+CC.
In can dim the leds with the potentiometer.
so with this driver it could be possible?
It ain't a problem if the fans go slow.
Only thing is i don't want to damage my strips.
Major Blazer
Well-Known Member
Parallel wiring the strips and fans won't damage your strips but your 'problem' of an extra power cord is easily resolved with a small terminal block. Prawn Connery brought up a scenario I had alluded to and especially with your B series driver it will likely be the case that when dimmed, the fans will shut off prematurely. One thing I did when I first wanted to get into diy led was purchase a couple of partially bad old led fixtures from ebay. You can scoop them up $5 or less sometimes. An added bonus to learning a lot about wiring is that you get a bunch of free parts like heatsinks, drivers, fans, wires, terminals, blocks, etc. and will make thinking about projects like this a lot less overwhelming. Gl either way.