Can you imagine illuminating four numbers of 1 watt LEDs through a a few 1.5V cells? Looks quite impossible. But it can be done simply using a coil of ordinary speaker wire, a transistor, a resistor and of-course a 1.5V pencil cell. The idea was suggested to me by one the keen followers of this […]
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LED Flashlight Circuit using 1.5 V Cell
This LED flashlight circuit is able to power a Luxeon type LED with a single 1.5 V battery. This results in a miniature flashlight that will not run out quickly. By: P. Martin Basically it is a boost converter circuit which boosts the 1.5 V DC from a AAA cell and converts it into a […]
Gel Cell Battery Charger Circuit [Constant Current, Constant Voltage]
In this post I have explained what are gel cell batteries and also learn how to build a specialized charger for charging a gel cell battery, with full calculations. The proposed circuit works in two modes: it starts charging a discharged gel cell battery with constant current, until the full charge voltage is reached across […]
How to Make Dye-Sensitized Solar Cell or Solar Cell from Fruit Tea
The innovation of dye-sensitized solar cells has expanded the device’s potential up to the point where it might completely oust costly silicon solar cells. In the following post I have explained how you can easily construct this versatile dye-sensitized solar cell using very ordinary materials. This experiment relies on the concept of utilizing the organic […]
Series 2S, 5S Li-Ion Cell Charger using BQ7718
This BQ7718 series 2S to 5S series Li-Ion cell charger is designed to monitor the voltage of each of the li-ion cells independently, with reference to an internally set reference level. As soon as any of the cell voltage tends to go above the reference level, it triggers an internal delay timer. This delay timer […]
Digital Thermometer Circuit – Uses a Solar Cell for Power
The articles explains a digital thermometer circuit project that works without a battery. Instead of a battery the circuit utilizes a small solar cell and operates by deriving power from the ambient light available from the surrounding light sources. This allows the circuit to be extremely compact, light weight, versatile and hassle free while measuring […]