- Reaction score
- 4,325
I understand your requirement is to produce a timed on pulse whenever the switch transitions on to off OR off to on.
To my great shame I have never designed nor constructed or worked on small thermionic valve circuitry. The larger tubes yes. So I will leave the ECC82 technology demonstrator for you to do.Excellent toolbox parts solution. I have in mind a single-package solution using an LM339 - a=input buffer, b=inverter, a couple of diodes and c + d=window detector.
I have to admit that many of my quick solutions these days are just PICs. As much as I like to design circuits, I can usually get there faster by programming. On one occasion I had so little time to make a gizmo to send abroad, I built the hardware and sent an in-circuit programming cable with it, then while it was in transit built a copy, programmed and debugged it and then sent the hex file for the end user to upload. At the moment of dispatch I hadn't actually worked out any of the logic or math, and there was quite a lot of floating point that I didn't have a hope of programming in time. By building generic hardware, I didn't need to think about it at that stage.
But I do like tricky hardware solutions. I am seeing an opto-isolator inside a bridge rectifier, maybe a unijunction transistor. How about a couple of ECC82s? What about triggering on the transit time of a C/O relay contact? Two mercury switches connected by a spring?
For tireminnanzi - the Italian made bticino gate control system I have worked on only required brief negative going pulses to trigger the controller to do something. Ie. Signal line was normally high at say logic 1 5Volts and when it dipped down to 0Volts ie logic 0 the logic circuits detected this and registered it.
As Lucien has said we really need a much better interface specification from you. References and drawings or sketches would be nice to look at.