Wanted the flashlight to be squat so I could hold it in my mouth, throw it in mypocket, and lay it on a surface with the beam shootingup. I wanted to build it for about $15, which was around 1/4 what they were selling for when I started the project. Prices dropped. When the Dorcy 41-4262 got down to $20 and lithium batteries got down to $1. 50, it didn`t make sense to build my own flashlight. So I bought the
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Dorcy and published a link page: what I bought, how it performs, a collection of the led circuit references that I collected before I decided to buy. Then pretty decent looking multiple-led flashlights started appearing. I bought one and found it looked good and worked good, but had some problems with consistant light output. I had no time to play with a circuit design, so I just used it. When the price of a 9-LED flashlight got down to $4. 50 including shipping, It was time to play. At that price, about the price of a magazine at the news stand, a failed project is disposable. This flashlight met one of my design criteria; I can throw it in my pocket. It is too heavy to hold in my mouth, but I can do it better than with a Maglite. It puts out a nice spot beam and is good for searching out things in tight places. You can balance it so it shoots the light upward, But, the little rubber switch cover on the end doesn`t quite get below the metal surface and the flashlight is not stable aimed upward. I am still on my first battery so I can`t comment about light output as the battery discharges. So why am I overall satisfied with it A second review gives the numeric details and also concludes that it is a good performer. The second review states that the flashlight is unregulated, which I think is a little mis-leading. True, the dc-to-dc inverter is not a true regulator, but it does keep the light output above 50% of maximum...
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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