Quote:
Originally Posted by old_coot88
He's had two Emerson units show the same problem (running slow). Assuming they're synced to the powerline*, and it's 'dirty' with transients, would the spikes necessarily show as additive (positive-going), or could they induce negative-going dropouts?  I dunno, just wonderin'. 
* EDIT. That's assuming both units to be digital. |
I suppose it's possible for a circuit to be filtered heavily to avoid spikes and then miss a cycle if there is an occasional reduced amplitude one. I can only say I haven't seen slow running, only fast, on the cheap units I have owned.
In either case it seems to be a basic failing of something that counts pulses rather than something with inertia (a motor) that coasts through transients.