Even if a fluorescent tube it`s not a neon glow lamp and this page it`s not maybe at the right place, this circuit is very interesting because it uses an odd way to power a very common lamp. Like glow lamps, neon tubes are composed by two electrodes in a low pressure atmosphere composed by a mixture of gazes; usually argon and mercury producing UV
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light that is converted into white light by a fluorescent layer on the internal surface of the tube. When the tube is off no current can flow through it when the voltage between its electrodes is lower than a threshold voltage (it varies with the length of the tube from about 300V for the smallest ones, up to more than 10kV for the longest ones). To reduce this voltage by a factor of 10 and make the tube start better the electrodes are often heated by a current flowing through them. Depending on the start circuit this current may (or may not) be shut off after the tube has started. Once the tube is lit, the voltage between its electrodes falls and remain roughly constant even if the current is varied (between 30 and 100V depending on the length of the tube and on the gas inside). Fluorescent tubes are often powered with AC current, but with this circuit we will drive it in DC. Basically this circuit is a voltage doubler (composed by the two diodes 1N4007 and the two high voltage electrolytic capacitors of 10uF - 350V) that generates, when the tube is off, a DC voltage of more than 600V from a 230Vac main. Unfortunately this circuit doesn`t work with a 110Vac main. If a low power tube is used (for example 4, 8 or 12W) these 600V are enough to strike the it. Once the tube lit, a current starts flowing through the two capacitors of 470nF - 630V that causes a voltage drop that ensures the service voltage of about 30V for the...
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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