View Full Version : Some Circuits I have designed to help all of us in the modding community.

01-23-2009, 04:10 PM
These are some simple electronic circuits I have designed or modified. They are very basic in theory and on a level that anyone who can solder can create one. I design all of my circuits in Cadsofts Eagle Layout Editor.

These circuits are free to use and you can copy or modify them as you feel. If you use one of them in a case mod please just say thanks.

This thread will be an on going list so I am going to reserve the first 3 post spaces for future content. Thanks for looking and remember to say thanks if you find any of these helpful.

01-23-2009, 04:11 PM
1. Simple LED Fading using a 10K pot.
This Circuit is designed to fade 1-4 LED's from almost off to full brightness (brightness limited by input voltage)
This is a cheap circuit to build and can be built with just the components and wire. No PCB needed. I priced this out without the leds on Digi-key and the total was less than $3 US. With LED still under $4.

2. 10 LED 5 channel variable rate flasher.
This Circuit will flash 5 channels of 2 LEDs each at variable rates depending on the position of the trim pot. This circuit requires +12v from your PC PSU.
Priced out on Digikey sans LEDs and PCB will run about $10 for the components. The PCB will be in th 10-15 range. LEDS from ebay run about $10 for 50.


20 LED VU Meter / LED Flasher VIA Audio input.
This circuit uses a LM3915 Display Driver IC. When and audio feed is connected via pins 5 (positive audio input) and 4 (negative audio input) the leds will flash. Some dimmer than others. If you place the LEDs in the same order as I have them in the schematic they will br very bright in the center and get progressively dimmer out to the edges.

The IC in this circut is a little pricey at $3-4 each and is highly ESD sensitive. Wear a wrist strap when handling this IC. It is also best advised to use an IC socket when populating the board as to prevent heat damage where the pins contact the silicon circuit inside the chip. If you already have the leds I am guessing that this circuit would cost somewhere in the $10 range if built on perf board. All leds can be used and the IC is stable upto 35 volts. 12 volts from a 12v rail on your psu should power it nicely. To connect the audio I would either use the header pins on the board for a front audio port or wire in a audio jack with the left and right channels connected as one.


01-23-2009, 04:12 PM
Reserved for future content 2

01-23-2009, 04:13 PM
Reserved for future content 3

01-23-2009, 09:25 PM

01-24-2009, 08:30 PM
I love it. I'm a HUGE LED freak! BTW, if you guys need LED's.. www.ledshoppe.com. $7 shipped for 100 5mm LED's.


01-24-2009, 11:46 PM
+ rep for the link SGTM. I have been ordering my leds from ebay since lsdiodes went out of biz. I just stuck my last RWKY (robots will kill you) sticker on my soldering station last night. I'm going to miss those little stickers.

01-24-2009, 11:59 PM
nice work :bowdown:

01-25-2009, 12:15 AM
Added a new circuit schematic. The LM3915 LED VU meter / Audio led Flasher

01-25-2009, 12:15 AM
Dude, nobody was sadder to see ldsiodes go down than Drumthumper and I.

01-25-2009, 01:09 AM
Yea I miss them and their stickers. oddly enough the last batch of leds I got from them was bad. I ordered 50 super bright green and 50 UV for a UV oven project. all but 3 of the green leds have failed and 21 of the UV leds have failed. Out of about 1000 leds I ordered from them over the year or so I knew about them those last ones were the only ones to have any bad ones in the batch.