Showing posts with label Lights - Leds. Show all posts
Showing posts with label Lights - Leds. Show all posts
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 ).
- ferrite toroid, (can be found on power supplies, radio), and wire to wrap around the toroid, ( big toroid and more turns = more output power and voltage you get ) the method of wiring is shown under, (if you don't have the toroid try the other methods under).
- and Led or anything you can't drive with one battery like: leds, lighting a neon lamp, charging capacitors with high voltage, charging other batteries Ex: charging 3.6V batteries with 1.2V battery...
you can change the 1.2V battery with 9V to get high voltage output that can drive neon lamps...
you can charge batteries...
A demostration:
A different types of coils can be used
Thanks
This circuit shows how to build a simple flasher that can flash Leds, lamps, motors...
To make this circuit you need:
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 hig power transistors we can drive high power bulbs...
- Battery 3-4 V ( for 5V increase the resistors values).
- And leds 2.4V or any.
- A variable resistor of 1K-10K ohms can be used (in place of one 2.2k resistor) to change number of flashes per second ( from 1 to 10 Hz ).
One led or two can be used
Thanks
This circuit consists of negative resistance in transistors.
A number of demonstratons of this circuit have appeared on YouTube.
Thanks
A common NPN
transistor is used. In the circuit, a 1k resistor charged the 470u
uf capacitor until the voltage became large enough to get the
emitter-base junction to avalanche. At this point transistor turned on quickly and partially
discharged the 470 uf capacitor through the LED and the 100 Ohm current
limiting resistor. The current wavform, which is the voltage drop
across the 100 Ohm resistor, Peak current was 26 milliamps, and the transistor continued to
discharge the capacitor until conduction suddenly ceased at 6
milliamps. After the transistor stopped conducting, the
capacitor began
charging again, thus starting a new cycle.By changing C1 frequency change.
A number of demonstratons of this circuit have appeared on YouTube.
Thanks
This circuit is a simple flasher it can be used with car bulbs or just leds.
It consists of two tansistors, the flashing rate can be changed by changing C1 value.
It can flash globes, LEDs and pulse all types of devices such as motors, and piezo diaphragms...
