Tekpower TP3005T Variable Linear DC Power Supply, 0-30V @ 0-5A with Alligator Test Leads

It works very well, and is easy to use. You can adjust to every digit- to the 1/100th of volt and 1/1000th of an amp! It is very accurate and repeatable, as well as stable. The values are adjusted in real time-- that was not clear in the online marketing material, and it is a very nice feature. The only minor annoyance is that there is no way to set the timeout for adjusting the voltage/amperage. The timer times our the knobs in about 1 second, and then you have to depress the button again. I wish there was an option to adjust the timeout limit or disable it. This is only a minor complaint, though. The only other minor issue, which is common on all the power supplies of this value range, is the power spike at startup. Just remember to turn on the device and let it stabilize for a second or two before attaching anything and you will be fine. It is rated at 5 amps, though it is actually 5.2 amps. For anodizing, it takes about 4.5 amps for every square foot of surface area, so this can do an item with around 1.15 square feet of surface area at the normal anodization level, and a bit more if you want a softer anodization, and a bit less if you want a harder anodization. I am really happy with this item, and I now wish I would have bought the 10 amp version in case I ever wanted to do larger pieces- just in case.

Feels solid and well built. I have put it through various trials and it does exactly what it is supposed to do and accurately. Took me a minute to practice with limit setting techniques etc but got it down. The pvc handle did smell on unwrapping but one night in my garage and it was dissipated. No smells from inside machine as far as I could tell. I'm very pleased with purchase. I also prefer a well smoothed beafy linear supply for bench work. I have now done an open up. Main points are ... Very well assembled with clean and tidy assembly work Nice heavy transformer with primary and secondary windings separated by thick polymer slabs. Same for separation from transformer frame. Transformer mounting screws have lock washers. Transformer had a slight smell with nose right on it. Will go with warmth and use. High grade modern surface mount pcb behind control panel. Excellent soldering. Mains feed wire double insulated including heat proof where it goes past transformer on floor. All wiring terminals properly heat shrink wrapped. Properly rated caps. Very adequate coated steel case. Some high tolerance (gold) resistors in main smoothing area. Overall just a really nicely built unit with good components and build practices. Excellent heat sink/removal system at back for power transistors Great value.

I received the power supply in just a few days and in good shape. Like all good linear supplies, it is heavy because of the transformer. As advertised, it supplies clean power with very low noise - much lower than a comparable voltage/current switching supply. The case and display are very neat and functional. Because of some of the reviews, I was expecting the multifunction controls to be hard to learn, but after about 10 minutes, they all made sense and are easy to use. Although the instructions do not say so, you can enter a voltage or current and then get the least significant digit you want to use blinking. Then if you immediately start turning the control up or down, it will raise or lower the voltage or current smoothly while incrementing the higher order digits when you pass 9 or decrementing them when you pass 0. Thus, you do not necessarily need to set each digit individually as they describe. It also lets you search for a voltage or current that does what you are trying to do. All of the functions worked as advertised and are typical of quality lab power supplies. This power supply is not exactly cheap, but it is a fraction of the cost of most professional lab supplies. It is definitely worth the price. There are only three negatives on the whole power supply, and one very small one was the banana plugs on the power leads. The springs were tight in the jacks, but the contact between the springs and the plug was intermittent. Whether this was poor construction or an attempt to allow the leads to swivel, it caused temporary interruptions of the current that would cause extreme problems in either analog or digital circuitry. I removed them and soldered on new plugs eliminating the problem. You should definitely examine the plugs. If the spring swivels easily on the plug, you should definitely replace them with better plugs. (Radio Shack sells banana plugs.) The second negative is the very strong paint smell as it comes from the box. I finally put a light load on it and left it to run with the fan on for a day or so to finish curing the paint. This is not a long-term problem, but unexpected in a quality product like this. The fan is very quiet under 1 amp, but jumps directly to high above 1 amp (at least with a 2 ohm load.) On high, the fan is pretty loud. A nice upgrade for the design would be a fan that is true variable speed based on heat sink temperature.

This power supply appears to be a well built unit and, after figuring out the way the controls work, the supply seems to function quite well. Initially I thought the unit I'd received had a problem because the voltage control would only adjust in 10V increments; 0V, 10V, 20V, 30V, and that was it. As it turns out, you need to tap the voltage control knob to put it into "Fine" mode and then it adjusts as one would expect. The other thing to be aware of is that, once the voltage or current has been adjusted, the controls automatically go back into "Locked" mode after just a second or two so, every time you want to change the setting, you need to first tap the knob to get it out of "Locked" mode and then make the desired adjustment. I prefer continuously engaged controls but, after getting used to how these controls work, I don't consider this a serious impediment. While using this supply to test a bunch of small low voltage lamps I unintentionally shorted the output numerous times with the output current limit at various settings between 200mA and a couple of amps. The supply performed flawlessly and, so far, is still working well. This is as it should be, but some apparently less well designed supplies I have used don't do well with having their outputs shorted repeatedly in rapid succession. This one seems to handle it OK. No serious complaints so far. Based on the limited experience I have with this supply to date, I would say it's a pretty decent unit and, for eighty bucks or so, is a pretty good value. I hope this info is helpful.

This is a really good linear supply. A linear supply has much less electrical noise than a switching supply and is essential for audio and communications work. This one also has nice accurate displays and good functionality. Linear supplies require fan cooling at higher power levels. This one does not turn on the fan at low output levels keeping the sound levels to a minimum too. The voltage setting is a little cumbersome, each digit is set individually but the roll-over allows you to continuously adjust through the range if not as quickly as simple coarse/fine controls but with better control.

Many reviewers stated their power supply had a strong odor when they unboxed it. In my case, I detected no odor, either when I first unboxed it or after operating it for a while. Some reviewers also commented on the loud heatsink fan noise when 1 amp or more was drawn from the unit. I tried to quantify the noise level using a sound-level meter located 2 feet in front of the supply and pointed at it. The results were: a. room ambient noise with the unit off - 62 dB. b. unit on and loaded to less than 1 amp - 63 dB. c. unit loaded with 1 amp or more - 65 dB. By comparison, the sound level of a hair dryer set to maximum speed was 70 dB at 2 feet from it. Yes, the increase in noise level of the power supply's fan is definitely noticeable when the load draws 1 amp or more but I didn't find it annoying. Apparently, the fan speed is triggered by the current output and not the heatsink temperature. The fan has only two speeds - low and high. It is always on at low speed until the load equals or exceeds 1 amp. There is a good YouTube tear-down review of the supply - search for eapbg #27. This video shows there is a heat sensor screwed to the heatsink. But this sensor appears to be used only to shut the power supply down if the heatsink temp exceeds a certain value, but I didn't attempt to verify this. The skimpy User's Manual only has the following two statements on the subject: "OVER HEAT PROTECTION: If the cooling fan fails to run, the system will detect it and stop working to protect the system." "INTELLIGENT HEAT RADIATION: The fan speed changes with the output power to lower the noise." I measured the unit's current draw from the 120 VAC line with no-load and with a 1 amp load: a. Idling with no load = 190 mA = 23 watts b. 1 amp load = 450 mA = 54 watts Below the AC power cord connector there is a 4-amp fuse. It required considerable force to pull out the slide-in fuse holder, which contains the active fuse as well as a spare - a nice touch. Using a couple of different multimeters, the accuracy of the voltage display was good out to 2 decimal places. For example, I set the voltage to 12.02 volts and that is exactly what my multimeters indicated both with no load and with a 1 amp load. This accuracy was observed across the entire voltage range. Current readings had similar accuracy. You set the voltage and current for your application by pushing in the respective knobs. You push a knob repeatedly until the display steps to the digit you want to set and it blinks. Then you have a few seconds to turn the knob to make your change. If you don't make a change during this time, the digit stops blinking and the display goes back to the original value. When you first turn on the supply, and press a knob, the left-most digit always blinks. However, if after the unit has been turned on and you have changed a digit, the next time you press the knob, the same digit you changed last will blink. The supply does have a memory feature that will save your last voltage and current settings when the unit is turned off and restore them when it is turned back on I examined the turn-on and turn-off characteristics of the output voltage by connecting an oscilloscope to the output and obtained the results shown in the attached photo. On the left is an on/off trace with the output set at 30 volts with no load. Note the 8 volt spike when the power supply was switched off. This spike disappeared at loads above 1 Kohm. Also, at voltages less than 30 volts, I saw no turn-off spikes with no load. For example, the trace on the right shows the no-load turn-off at 12 volts. The voltage ramp-up times were about 100 milliseconds at 30 volts and about 50 milliseconds at 12 volts with no turn-on spikes. I could detect no AC ripple on the output - it looked flat, except for approximately 40 mV of noise riding the output from extraneous RF sources that were picked up by my unshielded leads. There are a couple of minor design issues with the power supply. One is the lack of an output On/Off switch to remove voltage from the circuit being powered without having to use an external switch, disconnecting one of the output leads, or just turning the supply off. As a result, I intend to build a small switch box that will plug into the output terminals for use when testing breadboards. Another design issue is the lack of holes in the output banana jacks for secure attachment of wires without banana plugs. But one could still back off the plastic covers of the banana jacks, wrap the bare ends of wires around the shafts, then screw the covers back down to clamp the wires. Also the output banana jacks have a non-standard configuration. That is, the chassis ground jack is located between the negative and positive jacks. This arrangement would prevent the use of, for example, a standard dual banana plug-to-BNC adapter. I also discovered a minor problem with respect to the green CV (constant voltage) indicator LED. When the front panel was viewed from slightly above, the LED wasn't visible. But if viewed from a little below eye-level, the LED was visible. It appears the green LED was bent slightly upwards on the imternal circuit card and this prevented it from shining through the small hole in the plastic bezel. The other 3 LEDs are all red and much brighter than the green LED and were visible at any normal viewing angle. Other than those minor issues, I rather like this little supply. Frequent use will determine if it has an acceptable long-term reliability.

The build quality as some of the other one star reviews mentioned looked fine. I did notice the odor but it dissipated quickly. Kind of strong new electronics smell. Unit powered up. Connected it to the multi meter. Gave me a voltage then it suddenly spiked in voltage. Just did it on its own. Killed the power. Thought maybe I had done something so tried again. Tried to adjust the constant current value, turned OCP on off...not much you can really do with this guy. Now the unit is in constant current mode and won't accept any voltage setting that will stick. Nothing I did would result in voltage from the outputs. Fuses looked fine. Maybe I got a bad one but looking thru the thread here I am not alone. Maybe its a luck of the draw. I did try to contact support. Nothing. I did go to the web site and all that is there is a pdf version of the manual. Really wish it had a reset of some sort but nothing that I can find. The manual does not really provide any info other than some buttonology. The price was nice and it would be great to have a cheap PSU for small jobs but this one isn't going to be it. I did ask for amazon to send me another one. I will update. I figured for the 60 bucks or so I may just keep it for parts if the next fails too.

The output voltage is surpisingly accurate - changing by 0.01 tracks correctly. I haven't yet checked the accuracy on the current but will not be surprised if it too tracks down to the 3rd decimal. I only gave the user interface 3 stars though because of some issues I have with it. You can select which digit to change the voltage (or current) by pressing the voltage knob. Each press rotates among the digits, the one selected is flashing so you can change it. The timeout is a little short though so you have to press it again if you didn't get it right. I think the timeout seems to be between 2.5 and 3.0 seconds, but the voltage output is immediately changed so I think the timeout should be more like 5 or more seconds. It beeps every time you press the knob and I wish that could be turned off, without opening the case and making a mod yourself. Also would be nice if you could change the direction of the rotation for selecting the digit - it always moves to the right and wraps at the last digit. If you want to get to the digit to the left for larger voltage changes you have to keep pressing and beeping to get there. It doesn't beep on the voltage or current change though so thats good. It will do a "carry" over, for example if you are on the .1 digit and keep turning it up, once it gets to .9 it will carry over and increase the 1's digit for example going from 0.9 to 1.0 etc.. I think some other reviews complain about the fan noise. When it comes on it is slightly to the loud side but not anything that tips my boat. It seems to come on triggered by current at 1 amp or more rather than at a certain power (IxV) or measured tempurature but I haven't taken the time to prove if that's the case. If your application frequently goes over 1A then you can always get a inexpensive fan to replace the one it comes with. A warning is in order: Note that it remembers the digit when you change the level. Once, I had it on 15 volts but switched to power a lower voltage circuit so pressed the knob until the 10's digit was selected and turned it to 0 to get 5v. A while later I needed to increase the voltage and, being more accustomed to a different power supply, reached up to increase the voltage and forgot it was on the 10's digit -- I would have turned it from 5v to 15 volts in one increment which would have fried my entire circuit, but at the last millisecond remembered to check it. After this near miss, after changing the voltage I click the knob one more time to move it to the next lower digit just in case I forget again. Overall its a decent supply for the price. I've been looking for another and after getting a "dud" DOA TACKlife power supply, also sold here that I'm returning for a refund, may consider another of this type. While I like this supply due to the stability and accuracy, I wanted to get one with a different user interface for when I don't need the detail.

Adjusting the voltage while the X0.00 Value is blinking you go from 00. to 20-30 V into your device and destroys it