Completely self-supporting garden lamps using solar cells as their energy source are gradually becoming more and more common. How do they actually work We took one apart to ¬nd out. From environmental and technical considerations, buying such a solar-cell garden lamp has a lot to recommend it. It`s a great thing that the energy necessary for t
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he lamp to burn in the evening can be drawn from the sunlight that is available for free during the day. In addition, such a lamp is enormously practical, since you can place it in any desired location in the garden without having to dig a trench through the lawn or ¬‚owerbeds. You are also free to change your mind about the best location for the lamp - something that would have unpleasant consequences with ordinary garden lamps. What makes up a typical solar-cell garden lamp A certain number of elements are in any case necessary for it to function. It`s clear that there must be a light bulb and some solar cells. However, the bulb is naturally not powered directly from the solar cells, so there must be a storage battery and a suitable charging circuit to allow the battery to be charged by the solar cells. In addition, the idea is that the lamp should only burn during the evening and the night, and that needs a twilight switch with a light-sensitive cell. It`s not necessary to do anything to switch off the lamp, since that happens automatically as soon as the battery is fully discharged. Some of the more luxurious models have a small fluorescent tube in place of a normal light bulb, and in this case a small converter is also necessary. However, the model that we examined contained a small 2. 5V/75-mA halogen bulb, and thus did not need a converter. As far as the electronics are concerned, the whole thing can thus remain very...
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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