Hello, I have a power supply. The voltage is variable between 0 and 12 volts and it gives an unchangeable current of 2 amps. Now I want to electrolyze with this, but the power supply burns because it flows too much. Now I want a circuit that limits the current and does not let the power supply burn. The output current for Electrolysis can vary between 1 and 2 amps. And the output voltage should be between 5 and 6 volts

 

There is a simple solution.

Set the power supply to 12 V.
You want a maximum current of 2 A @ 6 V into the load.
Use a 3 Ω 15 W resistor in series with the load. You can use three 1 Ω 5 W resistors in series.

Now adjust the power supply voltage to give you the required current.
You can measure the voltage across the 3 Ω resistance to calculate the current.
I = V / 3

 

Start the supply at 0V and turn it up slowly until you get the desired current. You cannot control both the voltage and the current. The voltage will be whatever it takes to get the current you want.

 

The supply does not " gives an unchangeable current of 2 amps." That is the rated maximum it can do. It is the load resistance and the supplied voltage that set the current.