Power LED Coin Cell Torch Light with Boost Converter

~ olikraus

To train my self with SMD soldering, I decided to build a Mini LED Light with some available parts in my lab.

  • Small: SMD parts around a LM2704 boost converter
  • Simple: Can we reduce the part number count?

Part List:

  • Coin Cell (CR2032) and Coin Cell Holder
  • LM2704 with 22uH and 100 Ohm
  • Power LED (9V, 1A, but will be driven only with 100mA here)
  • Push button to activate the LED

Schematic:

The LM2704 can generate a constant voltage or for this application a constant current. The generated current for the LED is ILED = 1.23V / 10 Ohm = 123 mA.

And this is how it looks like:

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