On review of the Ultrafire XML-T6 torch, I found the mode switching / mode memory so dysfunctional that it rendered the torch useless in my evaluation.
At Ultrafire XML-T6 LED torch – a fix for the dysfunctional mode memory ‘feature’ I gave a fix for that revision of the electronics, and updated it with description of a later fixed production model.
Years later, I bought two more of these due to switch failures on the originals… and guess what, the flash on power on returns.
Let’s pull them apart.
They have a new revision / version of the LED driver PCB, and it has provision for a resistor in parallel with the capacitor, but the resistor pads are not populated.
Above, the LED driver board with a 100k resistor added, it is the far component. This was an 0805 part that was on hand, but ideally should be a 0603. Continue reading Ultrafire XML-T6 LED torch – a fix for the dysfunctional mode memory ‘feature’ #2