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- Oct 6, 2009
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Yes, I am adding the mod to ALL meters I've yet to assemble.
I'll mail your caps out today.
Got the parts Ken thanks
Yes, I am adding the mod to ALL meters I've yet to assemble.
I'll mail your caps out today.
it is similair laserbee. Instead of your solution which only calls for a pair of electrolytic capacitors on the outputs of the dc/dc converter, this new setup also calls for 2 pair of bypass ceramic capacitors. both on the input and the output. 1 .01uF ceramic and 1 .1uF ceramic in series on both the input and output. so that's 3 pairs total. Ok I'm confusing myself. you have one 5v input that needs 1 .01uF and a .1uF in series. then your ±9v out requires a set of .1 and .01uF capacitors on each of the outputs. +9v and -9v.
So in reality, you've got 3 capacitors on the output using the electrolytic capacitors as well which are rated at 100uF 25v.
You got it. I wasn't happy with the way that the caps were filtering only a good percentage of the noise coming from the dc/dc converters. Mario ended up putting the dual dc/dc converters on his scope and saw that they were incredibly noisy so he's designed a completely new circuit which utilizes inductors as well as capacitors. I'm willing to share that circuit as well although the caps alone do filter out a good percentage. It's my personal recommendation that you use the newer filter circuit and I'm willing to forward components or $$ to purchase those components to anyone wanting to use the new circuit.
Ken
I will be including it for all of the unfinished meters. It's why I didn't finish them or ship them out. However the circuit is for everyone else to incorporate as well.