First off, why this supply uses a very thick wire for the 120V side is beyond me. It is very large in diameter, about 0.275", and very stiff. The wire gauge is needlessly large. 30 watts of reflected power at the primary is only around 0.4 amps of AC current, which is very small. Therefore, the first thing I did was cut off this cord close to the input of the power supply and splice in the male lead of a 16 gauge extension cord, which is much thinner and more flexible than this ugly black cord. I did not connect the green safety lead because as far as I could tell, it connected to nothing, including the aluminum chassis. I poked through the case's non-conductive anodization with my meter probe and tested for a connection to this green line. Nothing. Nada. So I left the green lead floating. (For those of you who are safety-crazy: look at all of Apple's power supplies. 2 leads.)
Next, the output. Here again we have a needlessly thick, yet short length of wire. For an electronics guy like me, it's no bother. But what's a guy who doesn't know how to solder supposed to do with it? There is certainly an assumption on this power supply that you, the purchaser know how to solder. I clipped this cord close to the chassis and then spliced in an 18 gauge lamp cord, taking note of which lead is positive (red) and which side is negative (black). At the other end of this lamp cord I soldered a pair of color-coded female banana plug receptacles, red and black. I then made another 18 gauge wire with male banana plugs at one end and soldered the other end to my LED rope leads. In this fashion, I can disconnect the power supply from the rope if needed.
(By the way, when I make my splices, I cover the connections with heat shrink tubing. Great stuff if you've ever used it!)
When power is applied to the power supply, it takes a little over one second before the LEDs turn on. I know this bothers some people, but switching power supplies like this take a while to power up. If this delay bothers you, don't buy it. I have no problem with the delay.
Measuring the voltage at the connection point of my LED rope (which will be slightly lower than the power supply's output leads due to the various resistances between the supply output and my LED rope), I measured 11.939V, pretty much dead-on.
I left the lights on for about an hour and then used my infrared thermometer to measure the supply's case temperature. I read about 102F (39C), and a nearby wooden surface measured 72F. Thus we have a temperature rise of about 40F (22C), which isn't bad. Bear in mind this is while delivering about 23 watts. If you draw more power, it will get hotter; less power and it runs cooler. I don't find 102F to be objectionably hot, although you may.
I'm content with this power supply. It does what a power supply is supposed to do: supply a well-regulated voltage of 12V and in a small package. On the other hand, the connectors at each end are horrid. If you are not an electronics person like I am, you will have to live with the stiff black power cord. You will also be forced to do SOMETHING with the 12V output leads. Good luck.
And yes, I recognize that once I cut the unit's wires, there was no hope for a return. If it goes bad, I will simply have to toss it and get another.
Good electrical performance, lousy mechanical interface. Three stars.
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Nice little power supply. The output measures at 12.07 with no load. But for my use it can make a high pitch humming/buzzing noise if the output is limited below 12 volts. I use this with a 12v dimmer (item #B003L4KKF2) to power some LED ribbons, and when I turn the knob to anything but off or full on the supply makes that noise. I'm not sure if it's the dimmer or the supply's fault. The dimmer is PWM (pulse-width modulation), so it switches the voltage on and off at a high frequency, which is probably why the power supply buzzes when the voltage is limited. I'm not sure if this will be annoying in the long run as this supply will be powering some LED strips that will most likely be dimmed. Maybe I'll just have to find a new 12v dimmer (item #B004AGZSQG) that doesn't appear to be PWM.UPDATE: I have found and fixed the cause of the humming/buzzing. It was the dimmer's fault. By putting 2 16v 1000uf capacitors across the input of the dimmer, I was able to reduce the buzzing by 99%. I'm sure the correct value of capacitor will fix it 100%.
Best Deals for Ledwholesalers 30 Watt LED Power Suppply Driver Transformer 120
I ordered this March 22 and received it March 24. Great service there! However, it was as dead as a doornail. I applied to Amazon to get it replaced and guess what Amazon will only refund on outside vendors merchandise. So, I have to ship this within 24 hours to get my refund and wait another few days to get one that (might) work.If/When I get one that works to power my LEDs, I'll edit the review and change my Rating.
Until then, I give it just one star for the rapid shipment to me.
[Edit 03/31/2011]
I thought I had edited this a couple of days ago and came back and it's not here. HUMPH. I'll try again!
Received the second power supply and this one had 12V as strong as should be. VERY pleased with the quick shipping and now that I have a working power supply, I'm good to go!
Cons: Short 12V leads. TOO short. I made do, but it's a tad frustrating.
I don't know what country these are made in, but instead of the INDUSTRY STANDARD Black/White/Green on the 120V side,
the cable is made up of Tan/Blue/Yellow Wire? Who does that? Had to use a meter to verify the conductors.
Pros: SOLID construction on the main body of the device. Seems built like a tank!
Overall, after all is said and done, I'd buy again. If fact, I know I will. My next project is cabinet lighting.
Honest reviews on Ledwholesalers 30 Watt LED Power Suppply Driver Transformer 120
UPDATED REVIEW 11 March 2012... 1 starwell, I no longer like this power supply. For the past couple weeks its been flashing on and off randomly. It only does it after being on for an hour or so... it will shut off for a second and then come back on. Sometimes it will just flash rapidly for 10-30 seconds. I've checked my wires and everything seems OK with the wires. It must be the transformer.
This thing lasted long enough that it can't be exchanged... but it failed so soon it only gets one star now.
Now its time to look for a better power supply. Maybe its time to hack a laptop power supply and use that? Time will tell what I figure out.
Be advised before you buy, it might just fail after 2 months of use.
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ORIGINAL REVIEW: 4 STARS
I installed this with LED undercabinet lighting.Flexible Light Strip 300 SMD Bright White LED Ribbon 5 Meter or 16 Feet By Ledwholesalers, 2026wh
I wired it with a switch on the wall, leading to an outlet inside one of my cabinets. I then mounted this power supply in the cabinet and ran the low voltage wire up into the ceiling and around to all the cabinets. I used some washers to space this out away from the cabinet wall about a quarter inch. I'm not sure how warm this gets when it is on... but I figure having some air space would help keep it cool.
Install was easy enough (I did it before the counters went in). I soldered the wires to the output wire of the power supply. Now that I've thought about it more... I should have used some quick-connect wire fittings to connect the power supply to the low voltage wires. If this thing ever dies it will be a royal pain to change it out (now that the counters are installed).
So if you install one of these, I would highly recommend getting some wire fittings to make the connection.
(hopefully this never fails so I don't have to change mine!)
PROS
it works. I've used it for almost a month with no signs of issues.
CONS
there is about a 1 second delay when you turn it on. This is somewhat annoying and it is the reason I downgraded it to 4 stars.
The delay happened from the very beginning I first turned it on when I had just 1 cupboard wired with lights (so about 3 feet of LED strips probably) and it had the delay then. Now I have about 1.5 rolls of the LED strips installed and there is still a delay. So it doesn't seem to be related to the load on the power supply.
I have pictures of my LED lights on that page. You can look at them there. I didn't take any pictures of the power supply... not much to see...
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