ATtiny LED driver for an RC car update

in project logs by DP | 1 comment

Rev B build

joeforker posted an update on his ATtiny LED driver for an RC car we covered previously:

This board delivers 100mA through 2 series-wired LEDs like a champ, powered by a 2S LiPo. Night drives are looking bright. The glaringly bright uncomfortable-coming-straight-towards-you high beam look has been achieved. :-)
As usual, mistakes were made. The through hole components fit for once, but I got the transistor footprint wrong and had to mount the BJTs upside down on the board to swap the emitter and base; the ATtiny was too wide, so I had to bend its leads under itself to make it fit; and worst of all I got the voltage regulator footprint wrong – bzzt! Removed the reg, and the rest works fine. This version will get used without the micro just for the voltage regulator circuit. On to revision C…
The trimpot sets the current between approximately 190mA – 20mA.

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  1. jd902 says:

    Yeah, first rule before sending out a design is to print out your circuit 1:1 and set down components on the layout.

    It wouldn’t have prevented a junction swap though, at least it would reduce headaches.

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