Cool pinball related circuits from Jeri Ellsworth

[SirPeale]

http://www.facebook.com/video/video.php?v=132249439281&subj=504189281

http://www.facebook.com/video/video.php?v=132232149281&subj=504189281

[drventure]

That is awesome!

Electrical engineering has always been my achilles heel. Software I can do in my sleep, but capacitors, darlington pairs, thiristors, ack!

Very cool and nice explanation too.

[digitaldj]

In the first video way to much circuit is used for a simple problem. When the lights are used in (what she called a grid), which is actually called a matrix.When you have the scanning freq it is just a squarewave output on the matrix lines. This is almost the same as rectified A/C and with a capacitor becomes D/C. So as long as you filter that square wave with a capacitor you eliminate the flicker because now it is D/C. Just a simple elecrolytic capacitor will solve the problem.

A cap on each led will do the trick along with the current limiting resistor.

[digitaldj]

I forgot to add the diode, you will need a diode, cap & current limiting resistor on each l.e.d.

[SirPeale]

Digital DJ: you should tell her that.  I'm curious what she'll say.

[digitaldj]

Actually I got to thinking about it and each led doesn't have to have a diode and cap it can be done on each pulsed line of the matrix. This makes it even more simpler.

I will post on her page and see what she says.

[digitaldj]

Sir Peale,

Where is your store? I tried to go there but i'm getting nothing!

Kevin

[SirPeale]

I'm having server issues @ the moment.

[digitaldj]

Send me an email when your up.

[SirPeale]

Hope this link works: http://www.facebook.com/home.php?ref=logo#/jeri.ellsworth?v=feed&story_fbid=258600015216