Electronics > Beginners
1 HZ generator based on crystal (32.768 khz) issue
Mate_Well:
^ i have thought i'm insane when i done that on my last project (forgot vcc on 555 timer) and heureka found the issue resistance was wrong, but not on resistors :-BROKE, i have been close with the flux/rosin messing things up, except it was the vero board, measured 5M betven 2 pads, that would explain a lot of things, i have used this board in psu and other projects soo i never gave it inspection, but fact is i have never ever yet used resistors with value over 1M, sooo that explains a lot of headache, and i just jumped to finding issues with ic, crystal, and connections when all the time it was the pcb/vero board (for once it wasn't my brain with it's last 2 braincells completly failing :p )
Thanks all who helped you guys taught me a lot in the apst 2 days, and i hope this might be helpfull to someone
and as always, the problem is always the biggest bs that it could have been <3 u guys
and it is not technically solved yet, i will take cold one for that and hopefully finish a working board today (and i have a new thing to test when i will try to use pcbs) thankfully i have failed projects with pcb that i can still "salvage" but i would never ever thing about this being it (realised when the resistance of the series 6M8s was like 3M) :-DD
soldar:
--- Quote from: imo on October 26, 2019, 07:49:43 pm ---In case you would need to tune, you may try with a gimmick capacitor (a 5mm short long 0.2mm thin twisted wire) ...
--- End quote ---
I have used this trick in the past and it works well.
A couple years back I was repairing an old CRT TV that had problems with the color and it turned out that the frequency of the oscillator had drifted a tiny bit but just enough that the TV decoding part was not working. The frequency varied ever so slightly with temperature so the color would start failing after a while of use. It took me a while to figure it out but in the end adding a few pF in the form of a couple twisted wires brought the frequency back to where it should be.
iMo:
Decades back I tried to adjust my counter's oscillator, the 22pF trimmer was sooo coarse I had to go with the gimmick cap. You twist for example a 12mm long one, and then slowly cut off the free end, 0.5mm steps, till you get the frequency. When you cut off too much of it? Twist a new one :-+
Navigation
[0] Message Index
[*] Previous page
Go to full version