After constructing the Pulse Width Modulator for High Power LEDs I needed to build another LED modulator for another optical transceiver. For this project I decided to take a different approach and use solely linear techniques for the audio modulation. Like the PWM circuit, this circuit also uses the `precision current sink` to regulate set the LE
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D current but in addition to the linear modulator, a tone generator - based on the same source code as in the PWM circuit - was added to facilitate testing and aiming. In order to linearly modulate the intensity of an LED it is necessary to vary the amount of current flowing through the device rather than the voltage across it. It is fortunate that the luminous output of an LED is linearly proportional to the current flowing through it: At higher currents, the "current versus light output" curve "flattens" a little bit, but this results on only a very small amount (a few percent at most - see the sidebar below) of distortion and is unnoticeable in voice communications.
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.....
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