There are so many LED chaser/scanner/sequencer circuits out there, some are made with discreet transistors, some based on logic ICs, and more and more others are using microcontrollers.
There is one thing in common with all of the LED chaser circuits you find on the net - none of them can operate with just one alkaline battery!
Most of us know that LEDs need at least 2.2V or so to light. Blue and white LEDs require even higher, typically 3.2V. So obviously you can't use just one AA battery to operate an LED chaser. But we all know that there is Joule Thief that boosts voltage high enough to light any LEDs. Why not use that to operate an LED chaser?
Joule Thief is a nickname for this simple voltage boost circuit, predominantly used to light LEDs with one battery cell. However Joule Thief can be used to power more than just LEDs. I decided to power a microcontroller circuit with Joule Thief. (Although I ended up still lighting LEDs.)
Step 1: Features
- Compact & streamlined design.
- Uses only one AA battery (or any 1.5V battery you can hook up to).
- Works well with rechargeables (NiMH or NiCd) too.
- Eight LEDs, each with its own 256 level brightness control.
- Energy efficient - works even with a run-down battery, down to 0.6V (0.8V to startup).
- Versatile PIC microcontroller based LED chaser/scanner/sequencer.
- Many light animation patterns to choose from.
- Speed control via multiple taps of a button (double/triple taps to speed up/down).
- Start up "Quick-select" mode to choose from top 8 of over 16 patterns.