How to choose the best benchtop DC power supply

Working on the prototype of one of the new Bike Pixel models, I started to miss a benchtop power supply. They are devices that provide us with a regulated DC voltage and current. This makes them ideal for testing our designs, new components and prototypes. It is one of the tools that should be present in any electronics workshop.

Imagen de un voltímetro para ilustrar la medición de voltaje que puede proporcionar una fuente de alimentación regulable.
Voltmeter. Picture by Thomas Kelley.

There are a multitude of options, so we must select the one that best suits our needs and budget. You must take into account its characteristics but also other factors such as quality and safety. A good regulated power supply must provide a stable and accurate voltage and current, with minimum noise at any type of load. How well the power supply fulfils this task and where it reaches its limits is defined in its technical specifications.

Technical specifications to be compared

Although the technical specifications can be very exhaustive, when choosing your benchtop power supply, it is advisable to look at least at the following parameters:

Maximum voltage and current

Most benchtop power supplies move in voltage ranges between 0 and 30V and currents from 0 to 10A. If our projects are outside this range we will have to work with more specific (and also more expensive) equipment.

Number of channels

Specifies the number of current outputs. Normally one will be enough but as we begin to work with more complex circuits we may need some extra sockets. They are more expensive but the investment is worth it in the long run. In addition they allow different working modes being able for example, to connect the outputs in series or parallel in order to allow higher voltages and currents.

Resolution

The resolution is how small a change can be made on voltage or current. Unless we are dedicated to circuit analysis or work with very sensitive components, equipment with a resolution of 10 mV and 1mA will be more than enough.

Accuracy

It determines the difference between what you see on the display and the actual value output by each channel. Usually only a few mV and mA. As you have probably already guessed, more accurate equipment is more expensive.

User interface

DC power supplies usually have different controls for setting voltage and current and displays showing the selected values.

In more modern and advanced models, these are complemented by screen displays that include memory setup, current charts, signal programming and other additional information.

Animation with different screen modes on a programmable power supply.
User interface example with different visualization modes on a professional Keysight E36300 Series DC Power Supply.

Linear or switched

Depending on the way they convert alternating current into direct current, bench top power supplies can be either linear or switching:

  • Linear power supplies use classic transformers and are therefore usually larger, heavier and less energy efficient. But among their advantages are that they are usually cheaper, generate little noise and ripple at the outputs.
  • Switched power supplies work by filtering alternating current into pulses with a frequency of around 60 kHz and feeding it into a transformer. They are much smaller, lighter, more efficient and therefore give off much less heat. But the signals generated can be noisy and they are usually somewhat more expensive.

Programmable or non-programmable

To be able to perform automated tests and more in-depth testing of our prototypes we can consider using programmable laboratory power supplies. They are somewhat more complex and intended for more advanced users. Include a more complete interface and the possibility of connection to our PC via USB or serial port allowing us to program sequences of voltage and current values. Thus we can analyze how our circuits respond to different situations and check how our prototypes perform under anomalous situations.

Tips before you buy

Beware of clones

Sometimes the same equipment is camouflaged with different brands by simply modifying the name, adding a certificate or some other accessory and of course increasing the price. For example in the following case we have the same adjustable power supply but with different prices being the original manufacturer SIGLENT, with a price of $399 and two clones one of the brand RS-Pro (at $528) and another Teledyne (at $815).

Original Siglent Technologies SPD3303X-E Benchtop power supply.
Original Siglent Technologies SPD3303X-E benchtop power supply. Price $399.00
Cloned DC power supply that looks the same as the original byt changing the company logo to RS-PRo.
RS-Pro RSPF 3303X-E cloned DC power supply. Price $528.09
Cloned DC power supply that looks the same as the original byt changing the company logo to Teledyne.
Teledyne LeCroy T3PS3000 cloned power supply. Price $815.00

Safety measures

Best benchtop power supplies are equipped with various safety features. They are designed both to protect the power supply from misuse and to prevent damage to the electronics that are powered by them. Therefore, before purchasing a power supply, it is important to check that it includes safeguards against:

  • overheating,
  • overvoltage and overcurrent (OPV and OPC),
  • short circuits.

All of the adjustable power supplies listed below are equipped with these safety measures.

Comparison of best benchtop power supplies

Following you can found all the power supply models that I was comparing before buying mine along with links where you can purchase them.

In general they are all pretty good and you can use them in any project. Normally with a single channel will be more than enough but for more professional uses we can opt for more channels or sources with greater precision.

UNI-T UTP1306S

This is a DC power supply model quite affordable and designed for anyone. It presents a very simple interface in which we can adjust voltage and current.

It has all the safety measures available in the more expensive models and. We can set both the maximum current and voltage limits (with the OCP and OVP buttons respectively).

As an added bonus, its accuracy is quite good and it has three memory buttons to save our most common settings.

UNI-T UTP1306
Range Voltage 32V
Intensity 6A
Resolution Voltage 0.01V
Intensity 0.001A
Accuracy Voltage ≤0.1% ±5mV
Intensity ≤0.2% ±3mA
Channels number 1
Programmable No
Type Switching
Size 11.2×7.6×4.4 inches
Weight 4.17 Pounds
Price $99,98
UNI-T UTP1306S technical specifications table.
Image of a front view of a Uni-T UTP1306 DC power supply set as it max voltage (32V) and intensity (6A).
UNI-T UTP1306S switching benchtop power supply.

KIPRIM DC310S

Although I have hesitated a lot if not save a little more and buy a model with more channels in the end I have opted for this power supply. It is a programmable laboratory power supply and has a modern user interface.

Apart from the DC output channel it has two USB ports, one with a fixed output of 5V and up to 1A and another (on the back) that allows us to connect it to our computer (only for Windows unfortunately). In this way we can update and control the device.

In addition, unlike the most common models, it has a 2.8-inch TFT screen that gives a more modern touch to its user interface with different display modes and more saving and configuration options.

KIPRIM DC310S
Renge Voltage 30V
Intensity 10A
Resolution Voltage 0.01V
Intensity 0.001A
Precision Voltage ≤0.1% ± 20 mV
Intensity ≤0.1% ± 10mA
Channels number 1 + USB 5V1A
Programmable Yes (USB PC)
Type Switching
Size 8.9×3.2×5.6 inches
Weight 4.34 Pounds
Price $139.99
KIPRIM DC310S technical specifications table.
Front view of a KIPRIM DC310S benchtop DC power supply showing intensity and voltage time series curves.
KIPRIM DC310S programmable benchtop DC power supply.

RIGOL DP711

Before moving on to devices with more than one channel and simply as a comparison I leave you with this professional regulated power supply. Its price is quite high but in return we get a very accurate device with an advanced user interface including a 3.5 inch LCD screen. Not suitable for beginners.

It allows to obtain very stable and noise-free signals with a very high resolution. In addition, the manufacturer offers a 3-year warranty so we can assume that it is a very durable equipment.

RIGOL DP711
Rango Voltage 30V
Intensity 5A
Resolution Voltage 0.01V
Intensity 0.001A
Precision Voltage ≤0.01% ±2mV
Intensity ≤0.01% ±2mA
Channels number 1
Programmable Yes (RS232)
Type Linear
Size 13.1×5.5×8.0 inches
Weight 20 pounds
Price $403.84
RIGOL DP711 DC technical specifications.
Front view of a RIGOL DP711 benchtop DC power supply showing set intensity and voltage.
RIGOL DP711 DC professional benchtop DC power supply.

SIGLENT SPD3303X-E y SPD3303X

Moving on to multi-channel power supplies, the SIGLENT SPD3303X series are semi-professional devices and, as we have seen before, are also cloned for other manufacturers due to its good quality. In this case we have 3 channels. Two of them are fully adjustable and a third with standard outputs at 2.5V; 3.3V and 5.0V with up to 3.3A.

It has a very attractive interface and a large 4.3 inch display that allows different display modes. In addition, this model has a high precision version (SPD3303X) in which we can obtain signals with a resolution of 1mV and 1mA. Finally, it should be noted that apart from being able to perform its programming with the included software, thanks to its support for the LabVIEW controller we can use Python for its programming.

SIGLENT SPD3303X-E SPD3303X
Range Voltage 32V 32V
Intensity 3,2A 3,2A
Resolution Voltage 10mV 1mV
Intensity 10mA 1mA
Precision Voltage ≤0,5%±2digits ≤0,03%±10mV
Intensity ≤0,5%±2digits ≤0,3%±10mV
Channels number 2 + 1 up to 5V
Programmable Yes (USB PC)
Type Linear
Size 16 x 13.3 x 10.4 inches
Weight 17.6 Pounds 17.8 pounds
Price $399.00 $549.00
SIGLENT SPD3303X-E and SPD3303X technical specifications table.
Front view of a SIGLENT SPD3303X-E benchtop DC power supply showing set intensity and voltage for its two main channels.
SIGLENT SPD3303X-E benchtop power supply.

RIGOL DP832A

Finally I leave you another professional model. It has 3 independent channels, two of them up to 30V at 3A and another one up to 5V at 3A. It features very low output noise, excellent performance metrics and multiple analysis functions.

It has an advanced and very complete user interface on a 3.5 inch TFT screen. It also offers multiple connection options for programming including LAN, USB, RS232 serial port and Digital IO.

RIGOL DP832A
Range Voltage 30V
Intensity 3A
Resolution Voltage 1mV
Intensity 1mA
Precision Voltage ≤0.01% ± 2mV
Corriente ≤0.01% ± 250uA
Channels number 2 + 1 up to 5V
Programmable Yes (RS232,USB,LAN)
Type Linear
Size 9.4×6.2×16.5 inches
Weight 27.8 pounds
Price $672.00
RIGOL DP832A technical specifications table.
Front view of a RIGOL DP832A benchtop DC power supply showing output for each if its three independent channels.
RIGOL DP832A professional programmable laboratory power supply.

Conclusion and more information

The day finally comes when we need more than just our Arduino or that old cell phone charger to power or test our prototypes. That’s why a good adjustable power supply is a must. Before buying yours do not forget to check all the technical specifications and above all, if they have the basic safety measures.

Below are links to the full technical specifications of some of the equipment reviewed:


The links to the DC power supplies are affiliate links (except for the cloned ones). Every time you buy through them you will be helping a little bit to finance the project. Besides, it won’t cost you anything at all, since the price won’t change for you and we get a small commission for each sale. Thank you in advance! (The price of each product is indicative and corresponds to the price given in June 2022).

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