ATtiny13A PWM Controller + Cyclone from a Supermarket Jar

For Brushed Motors, Lights, Heaters and Fans

You can buy a cheap NE555 PWM module.

It will spin a motor.
It will dim a lamp.

But it won't do this:

• Soft start and soft stop (2.5 s up, 1.2 s down)
• Voltage compensation (run a 12 V motor from a 19 V supply)
• Overvoltage and undervoltage protection (9–25 V)
• Potentiometer hysteresis (no chattering near zero)
• Complete MOSFET shutdown (no leakage when OFF)
• Minimum PWM threshold for reliable motor startup

This one does.

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Gallery

Jar cyclone with mattress pump blower

Another view of the cyclone assembly

Schematic diagram

PCB layout in KiCad

Laser engraving the paint before etching

PCB after laser — ready for etching

PCB after etching

Board assembled and soldered

Flashing ATtiny13A

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Applications

Use it with:

• Brushed DC motors (fans, pumps, drills, cyclones)
• High-power LEDs and halogen lamps as a dimmer
• DC heating elements (soldering irons, hot-wire cutters, heaters)

With a regular power supply, it becomes a soft-start dimmer.
For heaters, it reduces the inrush current.

Same hardware. Different loads.

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License

MIT

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Power Limits

The controller itself does not limit power.

The real limits are:

• The MOSFET — current handling and gate charge
• The flyback diode — for motor loads

Choose the right components and the same controller can drive anything from a few watts to several hundred watts.

Same firmware. Bigger hardware.

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What's Next?

Replace the voltage divider with a temperature sensor.
Change a few lines of code.
Now it's a temperature controller.

Do the same with:

• Light sensors
• Humidity sensors
• Pressure sensors
• Any analog signal