LED High Power Light
R1: approximately 100k-ohm resistor (such as for example: Yageo CFR-25JB series)
R3: present ready resistor - see below
Q1: little NPN transistor (particularly: Fairchild 2N5088BU)
Q2: large N-channel FET (such as for instance: Fairchild FQP50N06L)
LED: power LED (such as: Luxeon 1-watt white star LXHL-MWEC)
energy resource: I used a classic "wall wart" transformer, or you might make use of battery packs. to power just one Light-emitting Diode anything between 4 and 6 volts with sufficient present will be fine. that is why this circuit is convenient! you need to use numerous energy resources and it'll constantly illuminate a similar.
temperature sinks: right here I am building a straightforward light without heatsink whatsoever. that limits us to about 200mA LED existing. for more current you'll want to place the LED and Q2 on a heatsink (see my notes various other power-led instructables i've done).
prototyping-boards: I did not make use of a proto-board in the beginning, but i built a second one after on a proto-board, there is some photographs of this at the conclusion if you want to utilize a proto-board.selecting R3:
The circuit is a constant-current origin, the worth of R3 establishes the current.
- LED current is set by R3, it's approximately corresponding to: 0.5 / R3
- R3 energy: the energy dissipated because of the resistor is roughly: 0.25 / R3
We set the Light-emitting Diode existing to 225mA by using R3 of 2.2 ohms. R3 power is 0.1 watt, so a regular 1/4 watt resistor is fine.
where you might get the components:
all the components except the LED's can be found away from you can seek out the part numbers offered. the LED's are from Future electronics, their pricing ($3 per LED) is far better than anyone else currently.