Kiran,
A sawtooth waveform would point to a bad C1. A waveform of a much higher
frequency would be from an oscillation and more superimposed on the DC.
As long as you are going to do some soldering anyway, you should just replace
the 7805 with the drop-in switcher that you received
Hi all,
I know this isn't quite on topic (no neon), but I hope someone can help me
out since it does involve obsolete numeric display tech. I'm seeking a copy
of the datasheet(s) for the S-5000B 7-segment readout by Stanley Electric
Co., Ltd., or any model in the S-5000 family, or a generic
I should have said if I see oscillation from the 7805 that Jeff mentioned,
pointing to a bad C1. I may just replace it regardless.
Kiran
On Saturday, March 28, 2015 at 7:55:48 AM UTC-4, Kiran Otter wrote:
Hi folks, glad to find this group!
I've had a Tubehobby clock for several years, the
Well I finally got my scope out and gave my self a sort of crash course on
how to use it. It's a 1975 Tektronix 475. Last calibrated in 1986. :D I
found it on eBay about 10 years ago and it was cheap enough, I figured I
could at least play with it and learn something. Bought probes and all,
Easiest way to hunt for oscillations is to use AC coupling, and start with
100mV/division, and 100usec/division. The exact frequency of the
oscillation isn't important; what you want is less than 100mV peak-to-peak
of noise. If you see 60Hz noise, either your 'large' electrolytic cap
(usually
