This article is of interest only to readers whose bicycle lights are powered by a dynamo. The laws on bicycle lights in the United Kingdom are stricter than in most other countries and a dynamo is, therefore, a rarity in the UK. For safety`s sake, it is obligatory for cyclists in the UK to have the rear light of their bicycles on even when they ar
Click here to download the full size of the above Circuit.
e at standstill. Such a rule is, of course, also advisable in other countries, even when it is not mandatory. The super-luminous LEDs are not powered directly by the regulator, IC1, but via a timer, IC2. The timer is driven by a pulsating voltage with a duty factor of 10%. This ensures very low current drain and also that the reservoir capacitor, C2, can energize the LEDs for a long time. Capacitor C2 is charged when the bicycle, and thus the dynamo if this makes contact with the relevant wheel, is ridden. This happens via bridge rectifier B1, and low-drop regulator IC1. The output of the regulator is a steady +5 V. When the bicycle is in use, but at standstill, for instance, at traffic lights, the potential across C2 powers astable multivibrator (AMV) IC2. With component values as specified, the switch-on time is about 0. 02 s, but the LEDs are not energized until 0. 25 s have elapsed.
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: