Charge NiCd or NiMH batteries with solar cells. This circuit extracts the maximum power from a solar array to charge a battery stack. It employs the MAX856 boost converter and MAX982 dual comparator with reference. As a power source, the sun offers some impressive advantages over typical battery cells: It generates virtually limitless en
Click here to download the full size of the above Circuit.
ergy, requires no recharging, and is expected to last for another five billion years or so. Today`s more efficient, less expensive solar cells provide a practical means of converting the sun`s power into electricity to run our gadgets and gismos (see the appendix, From Photons to Electrons ). The only clouds in this otherwise sunny picture are. . . well, clouds. Because they often obscure the sun, it`s tough to design a system that can reliably provide power. The output current for typical monocrystalline-silicon solar cells directly depends on the amount of incident sunlight (Figure 1). For example, a typical hobby-grade credit-card-sized silicon cell has an open-circuit voltage of 0. 55V. Internal resistance causes a voltage drop as you draw current from the cell; but, as light energy drops below the level necessary to support the output load, the cell current-limits at an almost constant voltage. For a light level of one full sun (solar irradiance of 1kW/m ²), the cell provides a typical short-circuit current of 0. 3A. Maximum output power arises at the transition from constant voltage to constant current, typically 0. 484V and 0. 25 to 0. 275A at one full sun. This 0. 484V is too low for most applications, so solar panels usually connect the cells in a series/parallel combination that provides several amperes of current at about 12V. Such outputs are useful for many applications, assuming full sunlight is available...
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: