This is a basic circuit of a step up DC-DC converter which the output voltage is more than the
input, the circuit could be used to power a 9v or more devices from a 6v or even a 1.5v battery, charge batteries (3-12v) with 1.5v solar cell...
The circuit uses an oscillator using Schmitt...
Joule thief is a simple step up converter, that converts DC to DC, for example you can drive a 3.4V Led with single 1.2V battery, even if the battery is almost dead. It extract all the energy stored in batteries.
You need:
1Kohm resistor.
small NPN transistor ( for example 2N3904...
This circuit shows how to build a simple flasher that can flash Leds, lamps, motors...
To make this circuit you need:
4 Resistors, two 470-560 ohms and two 2.2K-10K ohms.
2 Capacitors, 47uF (or approach values ).
2 identical Small/power NPN transistors (any type will work), by using...
This circuit is a rectangular oscillator, that generates a square wave form, the circuit uses NAND logic gates, using CD4011 (contain 4 nand gates), the generated signal can be used as an audio alarm (by connecting a speaker directly to the output), or amplified and used as an...
We thought that limiting the current of recharging the batteries did the trick, but no! the electrolyte leaks from the end of the negative terminal, when the battery leaks, it loses in the best case 50% of its capacity. more leakage always ends with a small explosion, so another method...
