DP30V5A-L Step-down adjustable voltage converter

Good day to all!
I want to offer to your court a review on DC-DCConverter from the famous manufacturer RuiDeng. The site has more than once understood the more expensive products from this seller, but they cost almost twice as much, and the functionality, in fact, is not very different.


  • Input voltage range: 6-40.00 V
  • Output voltage range: 0 V 32.00 V
  • Output Current: 0-5.100A
  • Output power range: 0-160 W
  • Weight: 66g
  • Size: 85 * 58 * 26 (mm) (L * W * H)
  • Voltage setting voltage: 0.01 V
  • Output voltage accuracy: ± (0.5% + 1 digit)
  • Current setting: 0.001A
  • Output current accuracy: ± (1% + 3 digits)
  • Output ripple (full load 40 V to B 32 V / 5A): about 100 mV VPP

Packaging and appearance.
The board arrived in a foam box, inside there was a package with a board and a small instruction.

Board dimensions, length 8.5 cm

Width is about 6 cm.

Height 3 cm with plastic feet.

The reverse side of the board, only soldering, there are no elements there.

A few words about the element base.
The radiator has an IRF5210 transistor anddual diode Shotki RB085T. There are no elements under the radiator. To work with currents close to the maximum, the manufacturer advises to replace the radiator with a larger one, or at least add a cooler.

The controller that controls the 32f100c8t6b board is very similar to those that are installed in more expensive converter models.

Pwm controller TL594C

Step-down PWM DC-DC Converter XL7005A

Operational amplifier SGM8582XS8

At the input there is a 470 microfarad capacitor 50V at the steam output 470 microfarad 50V and 470 microfarad 35V

I think that I will not be much mistaken if I say thatthe board repeats much more expensive converters from the same brand, for example the RD DP3005, and by and large it differs only in control and indication, well, at a much lower price.
Unlike expensive models, where to indicateLCD screen is used, here two assemblies with four seven-segment indicators in each are installed as indicators. These often put in sets, collect electronic watches by yourself and it will not be difficult to find a replacement for them. The board is sold in two versions, the only difference is in the installation of indicators, soldering or cots. Cots are standard for 7 legs in a row, indicators for 6 legs, the manufacturer simply bit off one foot on the beds.
The upper indicator is designed to display the voltage, the lower to display the current.

About management
All controls are carried out by four buttons on the sides of the indicators.
The buttons are signed like this: - / in, + / out, set, on / off.
Additionally, three LEDs, IN, CC, CV, were soldered to the board.

Indicators have two modes of operation, normal,when current and voltage values ​​at the input / output of the converter are displayed, and installation mode, when the expected (set) output parameters are displayed.
Switching between the display of input / output values ​​is done with the IN / OUT buttons, they are also ±. When the input data is displayed, the IN LED also turns on.
Using the On / Off button, you can enable or disable the output of the board; if the output is disabled, OFF appears on the lower indicator.
To set the output parameters is usedSet button. After pressing it, the board switches to the output value setting mode. In the installation mode, the indicators do not display the actual output value, but the value being set. The voltage and current are set sequentially by bit, starting with the installation of hundredths of a volt and ending with units of amps. For voltage, you can set tens, units, tenths, hundredths of volts, for current units, tenths, hundredths, thousandths of amperes. Switch between digits with the Set button. setting the value with the ± buttons, when going through zero, the high-order bit changes up or down. Exit the installation mode either automatically, if you do not press the buttons for 30 seconds, or after passing the Set button of all segments. When turned on, the inverter automatically applies the last set output values.
Unfortunately, in the management and display is in mylook and a few fly in the ointment. At first, there is no indicator whether the output of the board is on or not; this can only be understood indirectly by the operation of the CV, CC indicators. Secondly, the setting of output parameters is applied immediately when the segment value is set, and not after the installation of all parameters is completed.
And if the first problem is solved simply by installingthe LED on the output, then with the installation all worse, by chance let's say by confusing the buttons ± you can get a difference of ± 10 volts or ± 1 amp at the output and burn the connected load. For me, it would be logical to make the application of the set values, say by long pressing the same Set button.
Some tests
Unfortunately, the most powerful PB that is now available is 32 volts with 2 amps, and I will use it. The HD35 and the incandescent bulb (like 36 V 60 W) will be used as the load.
First, a few tests with the load.
As promised manufacturer voltmeter readingsThe boards differ from the readings of the multimeter only in the last digit; on average, this is no more than ± 0.04V; for me, this accuracy is more than enough, so there is definitely a credit.
The converter is set to 6V 2A with the load changing the current, the voltage held.

The converter is set to 10V 2.5A, the load current is less than 2.5A, keeps the set voltage.

The values ​​on the converter are the same, but the load is wound on the 2.52A. The current limiting voltage has significantly decreased.

When enabled, what is the current limit?The board keeps the maximum value for the voltage stable, there are small jumps, but only in hundredths of a volt or thousandths of an ampere. At voltages up to 5 volts, the real voltage, according to the multimeter, is approximately 1–3 hundredths lower than the established one. At voltages above 5 volts, the real is usually higher than the value set by about the same value. The maximum current deviation from the set was 10 mA on the set limit of 1A.
The maximum that could take from BP 29.7V. The difference between the input to the converter and the output was almost 2 volts, but more than 1A of current, the light bulb refused to eat.

With these indicators looked ripple at the output.
The oscilloscope input is closed, the scan is 50 microseconds / div, the sensitivity is 0.02 V / div.

And this is how the current oscillogram looks like when the converter is in current limiting mode, a multimeter acted as a shunt.
The oscilloscope input is closed, the sweep is 5 microseconds / div, the sensitivity is 0.02 V / div.

A small video review, and this is a review, not testing.
A small conclusion.
In my opinion a very worthy alternative to moreexpensive counterparts. Yes, it is not as beautiful and glamorous as those with color displays, it has less functionality, although there is no functionality the same, there are simply no memory-type buns, graphs, remote control and so on. But to be honest, for me personally, accuracy and stability of output is much more important to me than a bunch of menus and memory cells, and just so the converter is fine.
I apologize in advance for spelling andthe grammar of the text, all the mistakes made are not made on purpose, but only because of ignorance and in connection with the imperfection of automatic text-checking programs.