It is difficult to make a power supply unit for a computer with your own hands. But there are devices that require only one voltage to work, unlike a computer. Power supplies for them can be made at home.
Instructions
Step 1
Calculate the power consumption of the power supply. To do this, pre-calculate the power allocated to the stabilizer by multiplying the voltage drop across it by the current consumed by the load. Add the resulting power to the power consumed by the load itself. Then divide the result by the transformer efficiency, which is approximately 0.7.
Step 2
Calculate the current consumed by the primary winding of the transformer from the network. To do this, divide the power in watts by the mains voltage in volts. The current will be in amperes. It is for him that the fuse must be designed, connected in series with the primary winding.
Step 3
Calculate the voltage for which the secondary winding of the transformer should be rated. Add the supply voltage to the load with the voltage drop across the regulator. Divide the result by the root of two.
Step 4
Select a transformer with an output voltage that matches the rated voltage and an output current that exceeds the draw.
Step 5
Choose a diode bridge that is rated for higher current consumption and a reverse voltage that is much higher than the sum of the output voltage and the voltage drop across the regulator.
Step 6
Connect the AC leads of the diode bridge to the secondary of the transformer. To the output terminals of the bridge, observing the polarity, connect an electrolytic capacitor. Its capacity should be from 1000 to 5000 uF, depending on the power of the power supply. The rated voltage of the capacitor must be twice the voltage at the secondary winding of the transformer multiplied by the root of two.
Step 7
Choose a stabilizer circuit depending on what output voltage and current are required. Assemble the stabilizer according to your chosen circuit and connect it to the filter capacitor. Equip the regulator with a heat sink if necessary. If you need to power a load that does not contain LW, MW or HF radio receivers, use a pulse stabilizer with increased efficiency.
Step 8
After assembling the power supply, make sure with an ohmmeter that there is no galvanic connection between the input and output. Place the unit in an insulating housing. Do not forget about the fuse in the primary circuit, and better - in the secondary.
Step 9
Test the unit by plugging it in. Connect the load only after making sure that the output voltage does not exceed the design voltage. Do not use expensive devices that are a pity to burn as loads.
