Archive for August, 2013

Transistor calculations for a 12V 300mA light via raspberry pi gpio pin

I am following this excellent page as a guide: http://teachmetomake.wordpress.com/how-to-use-a-transistor-as-a-switch/ Using it, I worked through my use case of an raspberry pi connected to a TIP120 to drive a 12V LED light. diagram from http://ctheds.wordpress.com/2007/10/30/tip-120/ What value of resistor should I use? I’ve seen several different values on web examples, so looks like I need to actually […]

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