A replacement for the HP-41 zebra connector

[mfleming]

(04-15-2017 06:43 PM)Dave Frederickson Wrote:  Now that I look at it a little longer, the bulges may be desirable as they would flatten out and increase the contact area.

The gap should certainly stay, as it would take up any slack or flex in the distance between contact ends. Looking at your photos, I'm having another thought on the 71B flex design. The contacts are at a 0.50" pitch, with each contact slightly wider than the space between contacts. If I were to try and lay down contacts and conductive traces on the flex circuit along those same dimensions, it would be pretty sensitive to misalignment.

An alternative might be to replicate the wound gold wire arrangement using a flex circuit. I could lay down tracks that are 0.010" wide spaced 0.020" apart (sorry for all the Imperial measures here guys, I'll probably have to translate to metric for the PCB house later anyway). No trace would be wide enough to bridge two PCB contacts, and you're likely to get two flex traces per PCB contact. If those two wide PCB contacts at the right end of the photo carry power, then they would get proportionally more current-carrying traces.

I'll see what that looks like by guesstimating PCB contact dimensions and seeing how they would line up with parallel traces. I'll also check minimum trace dimensions with the fab.

aurelio Wrote:I would like to solve a bad contact problem that sometimes worries my CL
let me know please if still in time I'll send you what is needed

Sorry, I sent the last sample to another member about a week ago! However, I'm hoping to finish up and order a larger supply in the next couple of weeks. I've been trying to figure out, with the help of others, the most reliable spacer material to use with the flex so I could provide all needed materials. Given a variety of fairly cheap and available materials will serve the purpose, I wonder if I should just provide the flex by itself (along with suitable instructions and suggested supplies). Naturally, all at material + labor + postage (plus a little lagniappe to recover the R&D investment )

We'll see soon I hope,
~Mark