A Printed Circuit Board designed and built by Peter Gutkovich.
The Variable PWM PCB is a PCB designed and built by Peter Gutkovich. It was designed with Autodesk Eagle and printed by JLCPCB. It produces a Pulse Width Modulation (PWM) square-wave signal. This signal can be modified with potentiometers VR1 and VR2. VR1 changes the signal's frequency, which can either range from around 0.7 HZ - 7 HZ (SLOW MODE) or 19.7 HZ - 216.7 HZ (FAST MODE). Switch S1 sets the board to FAST MODE if it is switched to the left, and it sets the board to SLOW MODE if it is switched to the right. Potentiometer VR2 controls the signal's duty cycle which ranges from 0% - ~100%. LED D1 indicates the signal produced by the board by flashing on and off depending on the signal. Click here for an in-depth explanation.
The board should be powered with a 9V Battery. Use the + and - pins to power the board. Use the OUT pin for the output signal, and the GND pin for connecting to the board's ground. Information on how to use the switch and potentiometers can be found here. Click here to see this board in action.
The schematic and board files can be found in the Hardware folder. Gerber files for production are in this zip folder. Also, an image of the schematic can also be seen right here.
- LM358P Dual Operational Amplifier DIP-8 (x1) -> Amazon Link
- NE555 Timer DIP-8 (x1) -> Amazon Link
- 10 uF Electrolytic Capacitor @50V (Generic) (x4)
- 100 uF Electrolytic Capacitor @50V (Generic) (x1)
- 0.1 uF Ceramic Capacitor @>9V (Generic) (x1)
- 10K Potentiometer (x2) -> SparkFun Link
- DIP-8 IC Socket (x2) -> SparkFun Link
- 10K Resistor (Generic) (x4)
- 1K Resistor (Generic) (x4)
- 3 Pin Slideswitch (x1) -> Amazon Link
- Male Header Pin (Generic) (x4)
- NPN Transistor @200mA/40V (Generic) (x1)
- LED @3V (Generic) (x1)