Tekpower TP-3005D-3 Digital Variable Triple Outputs Linear-Type DC Power Supply, 0-30 Volts @ 0-5 Amps

I ordered a Tekpower TP-3005D-3 lab power supply. I have also looked at the Dr. Merten and Mastech power supplies before I ordered. From what I can tell from the outside and from the reviews, the power supplies are virtually identical except for the company label at the top left. Since I only have one of the units, I cannot compare inner workings.Out of the box, the device appeared well made and robust. Packaging was adequate. It powered up without any problems, and I let it run all day and over night. The next morning, the voltages were still within 1% of what they had been the day before (measured with external equipment). Great! I was a little concerned when I heard the relays switching the taps, so I monitored the output voltage with a scope while I changed the voltage setting over the full range. While I heard the "tapping," there were no irregularities to be seen on the scope, both with and without load. Great again! When I ran a unit in C.C. mode, the forced air cooling kicked in after a while, which is of course what one would expect. The device has two fans in the rear that are a little noisy, but with only little current drawn, the unit switches them off and is then completely quiet. The LED instruments are very easy to read even in well-lit rooms, and their color code matches that of the C.C./C.V. indicator diodes. In all these points, the power supply far exceeds the expectations one would reasonably have for a device in this price range.The user manual is well structured but written in "Chinglish" - but it is still comprehensible.What is most sorely missing in everyday use is a vernier or multi-turn pot for the voltage adjustments. Only a light touch on the knob changes the voltage by a few hundred millivolts. Adjusting the voltage precisely with clumsy fingers can be a challenge but it is still doable.The manual suggests to use additional external cabling when the two independent supplies are used either in parallel or in series, suggesting that the relays used internally for that purpose cannot handle the full 5 A current. So when you use this unit in any of these modes, use external cabling as suggested in the manual, or else you are likely to fry the internal relays.The previous two points are what I can easily live with using a power supply in this price range. After all, multi-turn pots and/or verniers and 5 A relays are more expensive than what is currently used.Lastly, when I measured the left independent power supply (slave) output while switching the unit from two independent supplies to the two in series, the voltage jumped to rather high values (somewhere between 20 V and 40 V depending on the original slave setting) before it decayed exponentially (over about 500 ms) to whatever the master dictated. That is not so cool as it could damage some circuitry that might be attached during the switching. The master unit does not show that behavior. While I cannot think of a use case where one would need to have an external device attached to the slave while manually switching modes, it is still a "feature" I could do without. So when getting this device (which I still recommend), make sure there is nothing attached to the slave unit while switching the mode of operation from "independent" to "series" mode.In all, and when you heed the advice given in the manual and here, this power supply is a very good value. All quirks I encountered have straightforward workarounds, that of the missing vernier being mere patience and a gentle touch. I personally do not know of a better product in this price range. For professional use, however, I would recommend other devices that cost easily five times as much.

The product arrived well packaged and in good shape. I received the version with LED displays and orange power button.I used a digital MM to check voltages on all 3 channels. All worked OK. The variable outputs go up to 32V, so up to 64V when used in series.I tried the separate, series and parallel modes, they seemed to work as expected. I also tried the current limit function, which also seemed to work correctly. There did seem to be a bit of overshoot when powering up, but only a volt or 2. Still, need to be careful with low-voltage circuits, and connect after powering up.As others have mentioned, it would be nice to have an output on/off switch, and the included leads are quite flimsy and cheap, although the line power cord is fine. The instruction manual is also a bit challenging to understand, but does get the point across.Other than those minor gripes, I think its a good product and I'm looking forward to using it. I reserve the final star until after some actual use.

I purchased this supply to replace two very old Heathkit "regulated," current limit supplies and various wall-warts that I have struggled with for longer than I'd like to admit. Most of my work is with microcontrollers and associated low voltage single and dual supply op amp circuits. Lately, I have been dabbling in HF HAM radio tranceivers, which require more than the 500ma. that I had. I like to power up a new circuit with an adjustable current limit to avoid the smoke and damage. I really can't justify spending more for a power supply than I paid for my 200MHz oscilloscope. That said, I was looking for something that would satisfy my needs and started nosing around in Amazon. I selected the Tekpower TP3005D-3, which exceeds my needs comfortably and at a good price point. The two top positive reviews by James M. and Tim were quite thorough and completely sold me on the product, reassuring me about my main fears. Both were impressed by the construction and James M was able to power a direct conversion receiver which is shakey with a switchmode supply. Yes, I did read all the bad reviews and still pulled the trigger. I have never bought a single thing that didn't have plenty of bad reviews. Some people won't be happy with anything.I wish I could say that I tore the unit apart and confirmed all the specifications, but I don't have the time or equipment to do that. I would like to say "Thank you James M. and Tim for going to all that trouble for me."Instead, I opened the undamaged shipping container (from Kaito) and gleefully wished myself a Merry Christmas. The green and red LED displays are way cool and make me feel like a pro. Both supplies put out more than 32 volts, unloaded. Both supplies put out more than 5.4 amps into a .02 ohm resistor. Both supplies deliver .64 amps into a 50 ohm load without changing the output.Now for the bad. Yes, the cables are low quality and not long enough and I had to replace them with better stuff I already had. Yes, accurate adjustments would be easier if the pots were 10 turn units.All in all, I am absolutely delighted with my purchase and would do it all over again. I would also recommend the product to a friend whose trust I value.It also powers my cranky experimental regenerative receiver which once required battery power.