A while ago I realized 17mm was still too big for many lights. A few months later, I have finally gotten around to shrinking the pcb down to 16mm. While I was at it, I enlarged all pads bigger than they were on v3, and added the pot footprint (thanks pyro for the idea and .lbr). Also, instead of adding 1 or 2 more vias, I made all vias much larger than before. The only negatives I can think of vs the 17mm v3 board are:
- The two sides are now dependent, you can’t just cut a trace and have two distinct circuits
The spring pad diameter has gone down from 10mm to 9.5mm
The kind of spring bypass i do with silicon wire shouldn’t connect to the casing of the pot if the spring dosen’t bottom out, are you thinking of copper braided spring bypasses?
We could always do spring bypasses on the outside if the pot where in the way.
I think a slider switch in the middle of the spring is a better idea, but the switches I have are just barely too big. Has anyone found a switch smaller than 6.75*4.5mm?
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