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I bought DPS605U, a Chinese regulated power supply, with constant current function and modified it a little.

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The DPS605U is a regulated power supply with a constant current function that can output up to 60V 5A.

The four-digit display of voltage and current, with the voltmeter in 10mV units and the ammeter in 1mV units, is superior to other Chinese power supplies with three-digit displays. I bought it because it has a constant current function, so I can test the lighting of LEDs without a resistor, which seems convenient.

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I bought it from Aliexpress and it arrived with the tape wrapped around it.

DPS3010U 30V 10A/DPS305U 30v 5A/DPS605U 60V 5A/300W Switching DC Power Supply 4 Digits Adjustable Mini Power Supply AC 110V/220V

I peeled off the tape to appear the box.

Included are the outlet cable, the power cable, and the instruction manual.

Here are the specifications in the manual. The Input Voltage is 115V±10%, so it may not be able to show 100% of its capability at 100V in Japan, but I don't use 5A at 60V, so I think it's okay.

This power supply is designed to switch between 230V and 115V, so make sure the switch on the back is set to 115V.

There are two voltage knobs and two current knobs on this power supply. One side (COARSE) is for coarse adjustment and the other side (FINE) is for fine adjustment. By setting a rough value with the COARSE knob and fine-tuning with the FINE knob, you can make fine adjustments to the voltage and current.

Voltmeter accuracy

I checked if the voltage displayed on the power supply was the same as that displayed on the tester. The tester is a cheap one, so I don't know how correct it is, but I'll try.

At 5V, it was 4.96V.

At 12V, it was 11.89V.

At the maximum of 60V, it was 60.8V.

The error seems to be about 1%. There is a possibility that the tester is wrong.

Accuracy of Ammeter

When it is 1A, the tester is also 1A.

When it is 1.5A, the tester is also 1.5A.

At 1.695A, the maximum output for a 300W incandescent bulb load, the tester is 1.71A.

The ammeter was almost the same value as the tester.


Next, let's look at the noise that rides on the supply voltage when a load is applied.

At 1A load, I can see a ripple of about 20mV. There is about 100mVpp of fine noise.

At 1.5A load, the ripple was about 100mV.

Even at 2 A, it is about 100 mV.

When I magnify the fine noise with an oscilloscope, there is about ±200mV where the noise is large.

At 2.5A, the ripple is about 200mV.

At the maximum output of 61V and 2.8A when connecting 200W and 300W incandescent bulbs, the ripple noise was 3.6V. Apparently, the ripple noise tends to become extremely large after about 2.7A. There is also a small squeaking sound coming from the power supply.

The power supply normally operates at 115V, but since I'm operated it at 100V, 170W output might be the limit of this power supply.

Constant current function

The minimum setting for the constant current was a few tens of mA, and when I tried to set it lower than that, no voltage was produced. Therefore, it does not meet the needs of ordinary LEDs or other devices that need to be driven at about 5mA. If it is more than about 50mA, such as power LEDs, the constant current function can handle it.

No output switch

Most of the stabilized power supplies sold in Japan have a switch to output electricity or not. Therefore, it is usually possible to turn off the output switch, set the voltage of the stabilized power supply, connect the power supply to the circuit, and then turn on the output switch, but this is not possible with this power supply.

So, I will modify the power switch to be a switch for turning the output on and off.

Remove the screws and you can easily see the inside.

The blue and brown lines connected to the lower right are the lines coming from the outlet. This will be removed from the switch and the blue and brown will be connected.

The red wire leading from the top of the PCB to the terminal on the front panel is the + pole wire for the output. Cut this wire in the middle and connect it to the switch you just removed the wires from.

This completes the modification of the output switch. The power switch on the power supply itself is no longer there, so the power turns on when I plug it in, but that's okay.

I set the voltage and press the button that used to be the power switch before I modified it.

Electricity is now being output.

Now I can use the power supply conveniently.

New power supply

Until now, I have been using a repaired homemade power supply that my grandfather used when he was young, but from now on, I will be using a new power supply.

DPS3010U 30V 10A/DPS305U 30v 5A/DPS605U 60V 5A/300W Switching DC Power Supply 4 Digits Adjustable Mini Power Supply AC 110V/220V

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