It may not work with a simple variable resistor because at higher
settings, the current will increase enough to probably just burn out the
small piece of the pot track that's still in circuit. A fixed resistor
will also still be needed to limit the full brightness current. In order
to get a decent control range, without risk of over-running the pot's
track and wiper, I would suggest that a small transistor needs throwing
into the mix to control the LED current, whilst the pot is left the
low-current job of controlling the transistor's base. If I get time today,
I'll give it a try.

Arfa


Well I was assuming the original resistor was still in place, but yeah you
do need it.