Power supply capacitor

[Cassidy Nolen]

All,

 

I am working on a little (portable to be exact) project right now and could use some advice. I have a Flashback 2 running on the same power supply as the monitor it is being played on. I've got it running using the onboard voltage regulator and the monitor is using its own, but they are both receiving the same power input (6.9 VDC). Basically, when the game makes an audio sound, the screen gets a little jumpy. Not awful, but you can see there is some noise in the system.

 

Do you think I could just wire an electrolytic capacitor, say 100mfd, across the power input lines to filter some of that noise? The monitor I have it hooked to had a fairly extensive filter inline (I have since removed it because it was drawing too much current) so I assume the monitor needed it.

 

Thanks for any input you might have.

 

 

Cassidy

[A.J. Franzman]

I had a similar problem with the portable I'm working on. Adding a 100 uF electrolytic cap in parallel with a 100 nF (104) ceramic disc at the power input to the audio amp board reduced it greatly.

 

However, I still had some other intereference issues, so what I did to fix it was to put a ferrite bead in the lead to each sub-component (VCS board, screen, CCFL backlight inverter, audio amp, etc.) right after the power switch. Also, in the leads to the VCS board and the audio amp, I added an additional small choke (sorry, don't have the value handy).

Edited February 20, 2008 by A.J. Franzman

[Cassidy Nolen]

I'll try the cap trick, thanks. Do you have a picture of the slugs you used? I'm thinking the kind that are inside the old RF converter switches and wrap each wire through one?

 

Thanks again for the input. I think I am on to something cool here

 

C

[A.J. Franzman]

The beads I used are just like the ones found on 4-switch VCS motherboards. In fact, I think that's where mine came from.