I really like that last design, with the pot in there, it could be fine tuned or one could even eliminate the fixed value resistor with a jumper and only tune the pot. Maybe a thru hole behind the pot to allow for adjustment without taking it all apart? Please?
I’m not 100% on which pads we need to be using for the pot. I think the way you have it set at the moment will be fixed at the maximum value of the POT
It occurred to me this morning that as long as the bleeder resistor is on the cap after the D1 on the driver board we would still have reverse polarity protection.
Hmm, you're on to something here :-) . But in an assembled tail, the hole would be behind the retaining ring. How about a version with the pot on the spring side, right in the middle? The middle contact of the pot can be made the batt-minus to that contact with the compressed spring is allowed.
One thing, I believe in those little metal pots the electrical connection to the slider is also connected to the metal top of the pot, so if you swap the electrical connections of the pot, the metal top part of the pot is batt-minus and then it is no problem if the spring touches the pot.
Yeah…. Thats partly why I didn’t put mine in the springpad yet. I feel like I’m going to have to adjust it while power is applied to get it right anyways
LOL, I had missed that you suggested the pot-on-spring-side already, sorry about that :-)
The solder pad lay-out that I posted above is at least shared by two brands (SR Passives found on Ebay, Bourns found on Digikey) so that may be a desirable size?
Btw, in my EDC (that has a lighted tailcap) there is more than enough space and depth in the middle of the spring, even when fully compressed (a typical 3303 pot is just 1.5mm high)
Based on this diagram, I don’t think it matters which of the two legs you use, you’ll just have to turn the pot the opposite way. I think that’s how it works.
Perhaps to dot the i's and cross the t's, on the switch side the switch-pad that connects to the spring pad on the other side should not fully stretch to the edge to prevent a possible short to the tailcap-body.