[sdiy] thanks for replies - Blue LED

[Bert Schiettecatte]

Hi All,

I wanted to thank Magnus, ASSI, Paul and John, and anyone who I forgot, 
for the helpful replies of my blue LED question last week.

So... it turns out a charge pump would be a good circuit to deliver the 
necessary voltage/current. I'd like to learn more about charge pumps 
now, and how to calculate if the pump can deliver the current/voltage 
needed?

I did some experiments with 2 and 3 cell AAA packs and it doesn't look 
like a pump circuit with a hex inverter and some 10uF caps can keep 
delivering the necessary current/voltage for the LED (around 30mA)...

thanks,
Bert