Review last updated: June 8th, 2010
When I first started flying rc helis, I had a small charger that didn't need much of a power supply (PS from here on out) to feed it. Then about 2 years ago I stepped up to a larger charger and that required a larger PS. This is when I discovered the idea of a converting pc PS (see my how-to for more info). I converted one and it worked flawlessly for a while but eventually I found that I needed more power, or more specifically different power. See the larger chargers these days require greater than 12V to provide their full output. Most need at least 15V and some need 24V. So about a year ago I started searching for a replacement and that is when I found the 350W models on eBay.
eBay has many listings of what looks to be the same PS. The best way to find them is to do a search for "xxV 350W power supply" where xx is the voltage you want. They seem to come in models ranging from 5-48V, but the pertinent models for rc use are 12V, 15V and 24V. There are many sellers. I choose one that looked reputable and sent them my $42. About 2 weeks later I received a very plain box from China and inside was my PS.
This PS is entirely encased in aluminum. The unit is solidly made and feels heavier than it looks. The input voltage selection switch is on the side, and the connections, power LED and voltage adjustment are on the end. All the connections are screw terminals.
Removal of 6 screws and voiding the warranty sticker allows a view inside the PS. Inside shows a fairly sparse arrangement of components but unfortunately the PS does not have a lot of free space for installing things like a power switch or banana jacks. There are a few locations but it would be tight. The whole case is used as a heat sink to dissipate heat.
Overall the PS gives you the feel of decent quality and decent design. Nothing great but nothing scary either.
Making the leads and getting it setup
All you get when you buy one of these PS is the PS itself. The buyer will have to furnish both the input and output leads. The good news is that it is very simply to make a set of leads. I am going to show you what I used but there are other options available. For the AC wall input I used a computer power cord as I have about tons of extras at work. I just cut the cord the length I wanted and then soldered some spade connectors onto the ends of the wires. I then used shrink wrap to make it all look nice. For the DC output leads I used some extra 14awg wire I had laying around. I soldered spades on one end and 3.5mm bullets on the other. The reason for the 3.5mm bullets is that I use 3.5mm bullets on all my chargers and power supply leads.
Then I hooked up both leads in the correct locations. If you are not familiar with wiring up AC, do a search online for more help. In my case the cord I choose had standard wire colors in it; black goes to L (line), white goes to N (neutral) and green goes to ground. Next I connected the red output wire to the middle screw terminal on the (+) outputs and the black output wire to the middle screw on the (-) outputs.
There are other choices for the input and output of the PS. For example you could install banana jacks in the case for the outputs. A power switch could be installed, either on the cord or in the power supply itself. An AC power port could be installed to accept a standard cable. Or the whole unit could be mounted in a separate case and input/output ports could be installed in that case.
Using the power supply
Before I used the PS, the output voltage needed checked/adjusted. I could have used a volt meter but it was just simpler to use my charger. I connected the charger to the PS and plugged it in. The PS light came on and the powered up. Next I entered the test screen to view the input voltage and adjusted the potentiometer to find that I had a range of 11.7-17.4V to choose from. I adjusted the PS to give me about 15V, as that was the voltage I wanted.
I am not going to put the PS through any sort of tests for this review because I have been using it for over a year now. During this time I have used it for a wide variety of uses including everything from charging my cell phone with it using a 12V car jack adapter, to charging some 8s 5000mAh packs at 10A on my iCharger 208B (nearly 400W output from the PS required), and everything in-between. In all that time I have never had a single problem in the slightest with this power supply.
The PS runs very cool. The fan only comes on when the PS gets warm. For example when charging my 6s packs a 10A, roughly a 280W draw off the PS, the fan will come on about 15min into the charge cycle and then cycle off and on a few times before the end of the cycle is reached. When the fan does run, the power supply never gets past lukewarm. The fan is fairly quiet and is easily drowned out by the fan in the iCharger, even when running slowly.
These 350W eBay power supplies, also sold by some hobby shops now, may not be the prettiest and you will have to make your own loads, but they will do job well and for a lot loss money than most other power supplies out there.
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