Buck Toot?? A buck toot 7027-D-350mA, can I make one myself?

[justinpugh]

Hi I buy buck Toot`s for my LED`s however at $10 each is there an alternative.

I use a 6v, 600mah battery to power my Cree LED`s, the buck toot ensures that the mah is limited to 350mah.

Is there a cheaper way of doing this?? I run two LEDS from this Bucktoot in parallel so that 6V at 175mah each,,(I think??,, Well the bucktoot allows anything uptop 24v to flow but a max of 350mah., so 2 cree 3v 350mah lights I assume will run at 3V 175mah each??)

Back to the question,,,,is there another way of ensuring that the LEDS don`t run at lets say 1000mah and burn out??? or do I need the Bucktoot.



(for details on the buck toot (7027-D-350mA ),,,see LED Lights : LEDs Lighting : LED Light Bulb : LED Supply and the cree led is here also (White Cree Q5 XR-E Star)

Thanks for your help guys..

 

[dougy83]

You can try this place **broken link removed** for cheap led drivers

 

[Jaguarjoe]

If you want to roll your own, look at the bottom of pg 19 for an adjustable current regulator:

https://www.electro-tech-online.com/custompdfs/2011/04/LM117.pdf

If you use a 3.6 ohm 1 or 2 watt fixed resistor in place of the rheostat, current will be ~350ma.

LM317's are pretty cheap

There are many, many constant current circuits out there, this one works.

Running LED's in parallel without ballast resistors is not the best setup. The unit with the lowest forward voltage (Vf) will take most of the current. Vf varies from part to part and is uncontrolled. Running them in series ensures equal current through each one but this means you will need a source higher than 6 volts.

 

[ronsimpson]

With a 6 volt battery and a 3 volt LED the LM117 will be 50% efficient, while the buck thing is a switching power supply and clams 95% efficiency.