My solution to Auto Power ON Lilliput screen

**Arathranar** · 04-12-2005, 04:35 PM

Ooh! Thank you! Please post (many) pictures!

**ming** · 04-12-2005, 07:34 PM

the board is mounted on the back of the casing. second photo shows the whole board and 1st is how I soldered the resistor and capacitor -- the original resistor was removed. 3rd image shows where I grounded the cap on the back side.

**looneeii** · 04-12-2005, 10:56 PM

Very nice, thanks

**fantomas** · 04-12-2005, 11:09 PM

do the lights on the bottom stay on constantly now for the 8" as well?

**Arathranar** · 04-13-2005, 12:01 AM

Originally Posted by ming

the board is mounted on the back of the casing. second photo shows the whole board and 1st is how I soldered the resistor and capacitor -- the original resistor was removed. 3rd image shows where I grounded the cap on the back side.

What size cap / resistor did you go with? Ok - I know I could work out the resistor by digging up the details on how the color code but I'm sure you won't mind letting me take the easy way out by telling me

.

**shotgunefx** · 04-13-2005, 05:38 AM

Any specific reason to use an electrolyte cap as opposed to a non-polarized mylar or more rugged Tantalum cap?

**ming** · 04-13-2005, 07:28 AM

I used values in coyote's post -- 150k resistor and 10uF cap. I didn't pay attention to what type of cap, but for 10uF probably Al electrolytic ones are most common and cheap, I got a 20 assortment pack from radioshack for $4.29.

I think the button lights work as they should be, but I didn't pay much attention to that.

**Arathranar** · 04-13-2005, 09:31 AM

Its a different mod for the lights.

**phc** · 04-14-2005, 12:51 AM

Originally Posted by shotgunefx

Any specific reason to use an electrolyte cap as opposed to a non-polarized mylar or more rugged Tantalum cap?

Capacitor selection depends on many factors, Tantalums are great for voltage regulation to supress high frequency oscillations and have low ESR. Film caps are good for high voltage spikes, low leakage, etc..

In the case of the lilliput, you have a 5V signal that you are trying to delay. Super low frequency, super low voltage. No need to spec anything but a cheap-*** aluminum electrolytic, rated to 6.3V.

I use a 150uF, in combination with the on-board 10K-ohm resistor, giving you an RC value equal to a 150 k-ohm resistor with 10 uF cap.

23 cents at digikey

http://rocky.digikey.com/scripts/Pro...&M=UHE0J151MDD

Putting in a more expensive capacitor won't make it work any better.

**shotgunefx** · 04-14-2005, 02:01 AM

Thanks for the answer. I'll probably use the tantalums as I have tons of them.

Originally Posted by phc

Capacitor selection depends on many factors, Tantalums are great for voltage regulation to supress high frequency oscillations and have low ESR. Film caps are good for high voltage spikes, low leakage, etc..

In the case of the lilliput, you have a 5V signal that you are trying to delay. Super low frequency, super low voltage. No need to spec anything but a cheap-*** aluminum electrolytic, rated to 6.3V.

I use a 150uF, in combination with the on-board 10K-ohm resistor, giving you an RC value equal to a 150 k-ohm resistor with 10 uF cap.

23 cents at digikey

http://rocky.digikey.com/scripts/Pro...&M=UHE0J151MDD

Putting in a more expensive capacitor won't make it work any better.