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Topic: Hacking Lighter Plug Adapters and Why You Want To. Olympia, WA USA 21May2015 7pm (Read 33 times) previous topic - next topic


I'm doing a class/demo this Thursday about using those cheap lighter plug USB charger adapters. For a dollar, you can get a complete switch mode regulator circuit that is about the size of an LM7805 with heat sink, without the heat or inefficiencies.

Did you know that, from a very low current to the maximum rated current, a linear regulator's efficiency is Vout/Vin? So 12V into an Arduino with the on-board 5V regulator has an efficiency of 5/12 or about 41%?

But a switch mode regulator has an efficiency of 60 to 95%, usually lowest at very low current draw and above 85% over most of the range.

Come to the meetup this Thursday May 21 at 7pm.
Steve Greenfield AE7HD
Drawing Schematics: tinyurl.com/23mo9pf - tinyurl.com/o97ysyx - tinyurl.com/q7uqnvn
Multitasking: forum.arduino.cc/index.php?topic=223286.0
gammon.com.au/blink - gammon.com.au/serial - gammon.com.au/interrupts

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