I have been using a power supply for the last couple of years that I have been pretty happy with. It’s a Korad KA3005D that I purchased on Amazon. It has been a good, albeit loud, power supply that is easy to use and has always measured very accurately when verifying measurements with my DMM. I like the display which shows your current setting out to the 3rd decimal place, which combined with a pretty accurate display of the voltage and current makes for a nice setup where you don’t need to include your DMM for non-critical measurements of 10mA and above (like where you need verification, or the lack of sub mA measurement would mean you could be 10% or more off on the value). I built some 2 foot leads from over-sized 12ga wire soldered to banana plugs and large alligator clips to replace the supplied wires.
The voltage and current settings are easy and quick to manipulate. While a dual knob system where each has it’s own knob would be faster, switching between current and voltage is one button push, and the left and right arrow buttons allow you to move between the digits in the value you’re moving, making large jumps or precise low values easy. Memorizing the setting to one of the 4 memory functions is done by holding one of the memory buttons for a few seconds, and makes for simple switches between your most used settings with one button push. The only trouble I ever had with this unit was the power switch on the front gave out locked in the on position when I had it running on the same outlet as a 1500w heater, from then on I just used unplugged it in the back to turn it off.
Another great feature is being able to set the voltage and current and allow the unit to regulate itself. To test the Vf of an LED I just set the current to 5 amps and the voltage to anything above 4.2 and the unit will display the voltage it’s running at when it’s at 5 amps. you can do the same thing by setting the voltage you want to test (lower than 4V for things like XP or XM’s) and set the current to max and it will display the current it’s using at the voltage you had set. Being able to set all this with the output off, but the circuit connected is great, and since the display is pretty accurate no DMM is needed.
I never measured the noise of the unit, but it uses a variable speed fan that goes from moderate to noisy once the power supply changes from idling to fully loaded at 5 amps. I don’t work anywhere where the noise is an issue, but if you live in a place with thin walls and your significant other is a light sleeper you wouldn’t probably want to use it in a room that shares a wall.
Korad KA3005D Power Supply
So now that I’m playing around with higher currents than I originally expected to be when I bought the KA3005D I decided to go with a bigger replacement. I spent a fair amount of time looking at the options that were capable of 10+ amps at 30+ volts. I had decided that I was willing to spend up to about $300, which will buy a pretty beefy unit. The problem I had with pretty much every power supply was that they don’t display enough digits, and few of them had a switch that allowed you to turn off the output, requiring you to power down the entire supply to turn off the output. To me that is a huge deal-breaker. I like to connect ground to the steel clamp I use to hold the pill for soldering and positive to the driver spring to test, and run LED’s before assembling them with the light, and as a controlled way to heat them for dedoming. If the supply has to shut of completely you lose the ability to easily switch modes on the driver without having to manipulate your leads, which increases the chance of a mistake where a lead touches something it shouldn’t. There’s also the fear I have (maybe warranted, maybe not) that there is an increased likelihood of a voltage spike/fluctuation whatever, that could potentially cause damage to an LED if I have it hooked up when I turn on the supply. After spending some time deciding if it was worth changing my habits to accommodate something like a Volteq HY3010D or HY3020D, I found the higher output Korad unit.
Volteq HY3010D Power Supply
Korad KA3010D
I decided that 10 amps was going to be enough for me to test to full power 90% of the builds I could think of doing, so I bit the bullet and ordered the KA3010D from SRA Soldering Products through Amazon. Basically everything about it and the KA3005D is identical except for the higher current, and being a few inches longer and a few pounds heavier. The order was shipped quickly and arrived well packaged in a second box around the original retail box. Unfortunately when I powered up the unit there was a fairly loud pop a large amount of smoke started to roll out of the unit. YIKES! I powered it off and unplugged it and opened a return/replacement ticket with Amazon. SRA contacted me in very short order and asked if I would like a return or a replacement. I told them that I would like a replacement, but with the issue the original unit had I would appreciate them testing the replacement under load, and then leaving it on without a load for at least an hour to make sure it was going to work when it got here. Christine replied that they would be happy to test the replacement unit, and would include a return shipping label in the box when they sent the new one, for the defective unit. I have never had a return go as smoothly as this went. I told her she was welcome to email me the return label and I would get it in the mail to them sooner that way. Within 24 hours of the original communication they had sent the return label to me through email and had the replacement (tested) unit on the way.
When I received the replacement I tested it out and everything is working as it should. It appears to be just as accurate as the KA3005D was for the voltage and current it displays, which is a relief because I wasn’t sure how consistently Korad is producing their units. My suspicion about the pop and smoke show with the original unit I was sent was one of the main capacitors for the power supply went bad during storage.
For now I can recommend this unit if you can get the seller to do a quick load test and then let it run unloaded for an hour to weed out any that have hidden issues.I can DEFINITELY recommend SRA Soldering Porducts. As has been pointed out by other members here, everyone is happy when there aren’t any problems, it’s how happy you are after a problem has occurred that tells you how good a company is. They are a US company based out of Massachusetts so there are no language barriers if you are in the US, their communication was excellent, their prices are good, and they have made a happy customer out of me even when something went wrong.
My unit in it’s new filthy home.
