This page features a replacement circuit for the LM3909 LED Flasher / Oscillator using discrete components. The circuit is functionally the same as the integrated LM3909 but has a minor variations in values of the components used. The LM3909 can still found but is fairly expensive, one possible source is Futurlec. The LM3909 is also available through some surplus electronics
Click here to download the full size of the above Circuit.
sources but usually only in quantities of hundreds or thousands of pieces. Naturally the circuit will not be as compact as the integrated circuit but it does offer the ability to adjust individual component values and can be less expensive than the integrated circuit itself. Let`s blink some leds again. Well, fading could be more accurate term. Meaning of this article is to show you an easy circuit that lets you light up your case with slowly alternating colors or just to make your power led come alive. Color changing FireWheel could be also cool, what do you think This is by no means a step by step how to but I think that it will be enough anyway. In LM324 there are 4 operation amplifiers. We used only two of them so you have an option to build another similar circuit around the IC. This way you can use second potentiometer to control the another circuit and it`s fading speed etc. LEDs shimmer randomly as though on fire LED power supplies for AA cells 1. 5 Volt LED Flashers AC Line Powered LEDs Astable Multivibrator 9 Second Digital Readout Timer 9 Second LED Relay Timer 16 Stage Bi-Directional LED Sequencer, other sequencer and flaser circuits 10 Stage LED Sequencer 28 LED Clock Timer Fading Red Eyes Two Transistor LED Flasher 16 Stage Bi-Directional LED Sequencer Expandable 16 Stage LED Sequencer LED Photo Sensor Circuit I don`t know why, but people like blinking lights. You see LED chasers everywhere, in TV shows...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: