https://github.com/emesik/led-dimmer

A dimmer for 12V LED lighting up to 70W, using PWM and LC filter
https://github.com/emesik/led-dimmer

Last synced: 14 days ago
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A dimmer for 12V LED lighting up to 70W, using PWM and LC filter

• Host: GitHub
• URL: https://github.com/emesik/led-dimmer
• Owner: emesik
• License: unlicense
• Created: 2014-11-19T22:50:34.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2014-12-01T16:21:17.000Z (almost 10 years ago)
• Last Synced: 2024-10-15T22:27:59.985Z (29 days ago)
• Language: Prolog
• Size: 199 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README
  • License: LICENSE

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README

        
LED lighting dimmer

My aim was to create a dimmer for a long LED stripe which would go around a big room. I didn't

want to output raw PWM and have around 20m of cable acting as antenna, even though the frequency

could be low and theoretically harmless. For that reason the circuit has two modules:

	1. PWM generator with ATtiny85 microcontroller, two MOSFETs and potentiometer input

	2. LC filter with cutoff frequency just a bit above 150Hz

The final output is flat voltage depending on the PWM duty cycle. There is possibility, however, to

bypass the filter.

I used DTP-24 ferrite powder ring choke, rated up to 6A. That limits the circuit to 72W output.

The main MOSFET allows even 12A of continuous output at 25°C, so the max power depends mostly on

the choke you choose.

TODO:

	* So far tested it with tiny load. Must see how it behaves with a few meters of LED stripe.

	* The table of potentiometer to PWM duty cycle translation is still far from perfect and fails

	  to provide linear dimming.