Dimmable LED controller

[coolwaters]

is there a easy and cost efficient way to make a constant current dimmable driver? about 100mA to 1A?

im not a genius with circuits but if its simple i can probably pull it off.
and conversions or add-on on a driver to make it dimmable?

 

[Marduke]

You can use a constant current at 1000mA, then use a PWM circuit 10-100% duty cycle to get your variable brightness.

 

[coolwaters]

where can i get one of those in California?

 

[Gunner12]

You can get the drivers off of Dealextreme and such, the PWM, I'm not sure but a quick search might turn up some.

Also some buck, boost drivers can use a variable resistace pot(right term?) so you can dim it that way too.

 

[coolwaters]

those are way too expensive. around $30+

i couldnt find any with a wide voltage input and low amperage. the amperage is really really high.

 

[MrGman]

is there a easy and cost efficient way to make a constant current dimmable driver? about 100mA to 1A?

im not a genius with circuits but if its simple i can probably pull it off.
and conversions or add-on on a driver to make it dimmable?

and what's wrong with the already perfect Uniq Continuously variable tailcap?

 

[coolwaters]

so theres no way to change the mA output of a constant current LED driver? i need to buy one that already have that feature?

 

[Marduke]

so theres no way to change the mA output of a constant current LED driver? i need to buy one that already have that feature?

Some do (Fenix for example), but they are at discrete intervals instead of being continuous.

But keep looking, someone might make one.

 

[Gunner12]

From the little I know, you can change the current of some drivers by changing the value of the sensor resistor (right term?).

Maybe a variable resistant resistor can be used instead of a set resistor to change output.

 

[rmteo]

Sense resistors are typically very low value (less than 1 ohm) in order to keep the sense voltage as low as possible. Most LED driver chips try to keep the sense voltage to 300mV (0.3V) or less. The simplest (and most efficient) way to control brightness (make it dimmable) is to use PWM.

 

[Turbo Guy]

Not exactly the answer you are are looking for however the Tenery T60 Tactical uses such a circuite. Infinitely varialble from 0.02A to 1.0A measured at the tail using a Li-ion 18650@ nonimal 3.7 volts .