To regulate the power of various electronic devices, for example, heaters, motors, special circuits are used, called PWM controllers. This abbreviation stands for Pulse Width Modulation. Thus, the load is no longer powered by direct current, but by pulses, by adjusting the duty cycle of which, you can change the current in the circuit, and therefore the power.
Necessary
- - chip NE555
- - two resistors of 1 kOhm
- - 100 Ohm resistor
- - variable resistor 50 kOhm
- - three diodes 1N4148
- - capacitor 2, 7 nF
- - capacitor 1 nF
- - transistor IRFZ44
Instructions
Step 1
The first step is to prepare all the necessary parts for assembling the circuit. It is advisable to adhere exactly to the exact denominations, but if you failed to find them, it does not matter, you can put the closest ones. Diodes 1N4148 can be replaced with KD522 or 1N4007, the IRFZ44 transistor can be safely changed to IRF730, IRF630 or others similar.
Step 2
When all the parts are assembled, you can start manufacturing the printed circuit board on which the circuit will be assembled. It is made by the LUT method, because it is the most affordable and simple method for making printed circuit boards at home. The drawing itself can be drawn in computer programs, for example, Sprint Layout, or by hand with varnish. The drawing must fully correspond to the diagram, only then the board will be operational. Neighboring tracks should not run too close to each other, otherwise a short circuit cannot be avoided. After applying a protective layer of tracks to the textolite, the board can be etched. To do this, pour a glass of water into a flat plastic container, pour a tablespoon of citric acid and a teaspoon of salt. We mix, put the board, after about 20-30 minutes the excess copper will come off the board, and the solution will turn greenish. Now all that remains is to remove the protective layer with a solvent, drill the holes, tin the tracks, and the board is ready.
Step 3
When the board is ready, you can solder the parts. First, resistors, diodes are installed on the board, then capacitors, and last but not least, a transistor and a microcircuit. It is most convenient to lead the wires for connecting the load and power supply through the terminal block. After completing the soldering, it is imperative to check the correct installation, wash off the remaining flux and ring the adjacent tracks for a short circuit. The PWM regulator is ready, you can connect it to the power source, load and check the operation.
