Voltage, Current and Power

Three numbers, not two. A 30V 5A supply is usually a 150W supply, so you get 30V at 5A only if the wattage allows it. For microcontroller and sensor work 30V and 3A is plenty; battery packs, motors and LED strips push you toward 60V or double-digit amps.

Resolution and Accuracy

Setting resolution (10 mV / 1 mA on most of these, 1 mV / 1 mA on the Siglent) decides how finely you can dial in a rail. Accuracy is a separate spec and is where lab instruments pull ahead of modules. If you need the reading to be trustworthy, use a meter alongside a cheap module.

CC/CV and Protection

Constant current mode is what turns a power supply into a safety net: it clamps the current instead of frying your board. Look for adjustable OVP, OCP, OPP and thermal shutdown, plus an output on/off key so you can set values before anything is live.

Remote Control and Presets

This is the “programmable” part. Memory groups let you recall 3.3V/500 mA in one keypress. USB, RS232 or LAN with a documented protocol (Modbus RTU on the Riden and RuiDeng modules, SCPI on Siglent and Rigol) lets you drive the supply from Python for automated tests.

Linear vs Switching

Linear supplies (Korad, Siglent, Rigol) are quiet, with ripple measured in hundreds of microvolts, but heavy and inefficient. Switching modules (Riden, RuiDeng) are compact, efficient and cheap, at the cost of tens of millivolts of ripple and switching noise.

The DP30V5A is the cheapest honest way into programmable power. Feed it 6 to 40V from any laptop brick or 24V supply and it gives you 0 to 32V at up to 5A, set to 10 mV and 1 mA steps, with constant current, adjustable protection and 10 stored preset groups you can recall from the keypad. Two of those groups have dedicated quick-recall keys, which is exactly what you want when you keep switching between 3.3V and 5V rails.

What it does not have is a communication interface. The base DP30V5A is programmable in the preset sense, not the “drive it from Python” sense. If scripted control matters, step up to the DPS5005 or RD6006 instead.

The DPS5005 squeezes a 50V, 5A programmable converter into a module the size of a matchbox. It stores 10 groups of preset values with two quick-recall slots, shows set and actual values on a colour LCD, and this USB and Bluetooth version exposes a Modbus RTU interface so you can control it from a PC or an Android phone. It is the module of choice for people building a supply into a project box, a portable field kit or a 3D printed pegboard rail.

Compared with the RD6006 you lose the bigger display, the energy metering and 1A of headroom, but you gain a much smaller footprint and a lower price. Note that the DPS5005 tops out around 250W and that the tiny heatsink means sustained high-current work needs airflow.

When 360W stops being enough, the RD6018 is the obvious next step. Same interface and same PC software as the RD6006, but with 18A of current and a 1080W ceiling, a thermostatically controlled fan and a snap-in replaceable fuse. That is enough to charge large lithium packs, run e-bike and scooter controllers, drive high-power LED arrays or load-test a motor driver properly.

Two honest warnings. First, this pick sits well above the price of everything else in the modules section, so only buy it if you genuinely need the current. Second, Riden sells the RD6018 as a bare module, as a case bundle and as a full set, and listings vary, so confirm on the live listing whether the case and the AC-DC supply are included before you order.

The Siglent SPD1305X is where this list crosses from hobby gear into test equipment. It resolves to 1 mV and 1 mA on a 2.8 inch colour TFT with 5 digit voltage and 4 digit current readouts, holds its accuracy specification properly, and gives you a real timer and waveform display so you can watch the output over time rather than guessing. Remote control is standard SCPI over USB, with LAN available, so it drops straight into an existing automated test setup alongside PyVISA.

This one sits far above the budget picks on price, and we will say that plainly. What you are paying for is measurement you can quote in a report, a documented instrument command set and a manufacturer that supports the product. For a student bench that is hard to justify; for a lab or a small hardware company it usually is not.

The Rigol DP711 is a single channel linear supply built around one priority: a clean rail. Ripple and noise are specified in the hundreds of microvolts rather than the tens of millivolts you get from a switching module, which matters enormously for op-amp front ends, ADC reference rails, audio and RF work where supply noise lands directly in your measurement. It also has the solid feel of proper instrument hardware, with a clear display, timer functions and RS232 remote control.

The trade-offs are the classic linear ones plus one modern annoyance: the DP711 uses RS232 rather than USB or LAN, so most people will need a USB to serial adapter. It is also heavy and expensive relative to the modules. Buy it for signal integrity, not for features per dollar.

This is the answer to the most common complaint about the RD6006: that it arrives as a bare module. The set bundles the RD6006W, the matching S400 metal housing and a 400W switching supply, so you finish with a complete 0-60V, 0-6A bench instrument with WiFi and USB control for far less than a commercial equivalent. Buying the three pieces together also removes the guesswork about whether your input brick and case actually fit.

The important caveat is in the listing title: not assembled. You will be screwing the case together and wiring mains into the switching supply, which means you need to be comfortable with line voltage wiring and earthing. If that sentence makes you uneasy, buy the Korad KD3005P instead.

General maker bench?

The Riden RD6006 covers almost everything: 0-60V, 0-6A, presets, metering and scriptable control.

Want to plug in and go?

The Korad KD3005P is a finished mains supply with quiet linear output and USB plus RS232 control.

First supply on a budget?

Start with the DP30V5A and a spare 24V brick. Real CC/CV and 10 presets for pocket money.

Batteries, motors, high current?

The Riden RD6018 gives you 18A and 1080W with the same interface and PC software.

Analog, audio or RF work?

Go linear. The Rigol DP711 keeps supply noise out of your measurement in a way no buck module can.

Automated test with Python?

The Siglent SPD1305X speaks standard SCPI over USB or LAN and drops into a PyVISA setup.

What actually makes a DC power supply “programmable”?

The word covers two levels. The weaker sense is stored presets: the supply remembers several voltage, current and protection combinations that you recall from the keypad, which is what the DP30V5A offers. The stronger sense is remote control, where a documented protocol over USB, RS232 or LAN lets a PC set and read values. Riden and RuiDeng modules use Modbus RTU, Korad uses a simple ASCII command set, and Siglent and Rigol use SCPI, the standard instrument language. If you plan to automate anything, buy for the second sense, not the first.

Do I need a separate power supply for the RD6006, DPS5005 or DP30V5A?

Yes. All three are step-down (buck) converters, not complete supplies. They need a DC input that is higher than the maximum output you want, plus roughly 1 to 2V of headroom, and they need a case for safety. A 48V or 60V switching brick suits the RD6006, and any 24V laptop-style adapter is fine for a DP30V5A used up to about 22V. If you would rather skip the build, either buy the RD6006W complete set or choose a mains bench supply such as the Korad KD3005P.

Linear or switching: which should I buy?

Choose by what you build. Switching supplies (RD6006, DPS5005, DP30V5A, RD6018) are efficient, compact, cheap and cover wide ranges, with ripple typically in the tens of millivolts. That is invisible to logic, motors, LEDs and battery charging. Linear supplies (Korad, Siglent, Rigol) trade efficiency and weight for ripple measured in microvolts, which matters when supply noise would end up inside your measurement: precision analog, ADC references, audio and RF. Many benches end up with one of each.

Can I control these from Python or LabVIEW?

On most of them, yes. The Siglent and Rigol units speak SCPI, so PyVISA gives you commands such as setting voltage and reading back current in a few lines. The Korad P models take short ASCII strings over a virtual COM port, which is easy with pyserial. Riden and RuiDeng modules expose Modbus RTU registers, and community libraries for the RD6006 and DPS series wrap those into simple Python calls. The one exception on this list is the base DP30V5A, which has no communication port at all.

What voltage and current do I need for Arduino, ESP32 and Raspberry Pi work?

For pure microcontroller and sensor work, 0 to 30V at 3A is comfortable, and a hard current limit matters far more than the maximum. Set 3.3V or 5V with a limit of 100 to 500 mA when you power a bare board, and the supply will fold back rather than destroy a shorted rail. Add headroom if you drive servos, motor drivers, LED strips or a Raspberry Pi with peripherals, which can pull 3A or more in bursts. Only battery packs, e-bike controllers and power electronics genuinely need the 60V or 18A class.