Here is a simple and powerful LED based night lamp circuit that can be operated directly from the 230V mains supply. The are total 24 white LEDs used and the lamp produces an output of around 15W. The resistance R1 and capacitor C1 provides necessary current limiting. The circuit is sufficiently immune against voltage spikes and surges. I would str
Click here to download the full size of the above Circuit.
ongly recommend that you rectify the mains power and use a filter capacitor, the flicker when powering an LED array like that is quiet intolerable to most people. Most LED lamps I built, have not a capacitor but a resistive voltage divider, for more long term reliability and reducing the chance of the LED`s to fail, when the capacitor has a bad day at switch on and overload the 1k resistor. If there is high contrast, both between the light and its surroundings, and between the on and off phases of the light, it is quite easy to see 100 Hz flicker I move my eyes past the light. The off period is more important than the frequency. Lights lit from UK mains at 100 Hz usually have off periods of about 5 ms and aren`t as bad as the tail lights of some cars that are 1 ms on and 9 ms off. I can see that they are flashing at any distance from about 5 metres to a couple of km. Some car tail lights are now lit at about 400 Hz, which is still visible but isn`t nearly as distracting. I haven`t had a chance to get a `scope on one of them to measure for sure. Also, it doesn`t really matter that only a few percent people find 100 / 120 Hz lighting intolerable, you shouldn`t be subjecting them to lighting like that, any more than you should put door lintels 1. 8m off the ground and only 5% of visitors knock themselves out. Scotopic vision is more sensitive to flicker than photopic vision so you`ll notice flicker more under low light...
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: