Steve Rooke wrote: > 2008/11/30 Bruce Griffiths <[EMAIL PROTECTED]>: > > >> Since these devices actually store the reference voltage on an internal >> capacitor, it would be interesting/informative to plot the output as a >> function of time over several years/decades. >> They haven't yet been available for long enough to establish their long >> term stability in actual use. >> I wonder if one can recharge the internal capacitor should this prove >> necessary or if one wanted to adjust the output? >> This probably requires access to an internal node. >> During manufacture, a servo loop adjusts the output by changing the >> voltage on the internal capacitor until the output reaches the voltage >> of the external precision reference. >> The servo loop is then opened trapping the required charge on the capacitor. >> > > I guess that would require having a suitably accurate measuring > instrument with an accurate reference voltage in the first place. > > 73, Steve > Steve
Not necessarily, a stable (not necessarily having a known absolute error) standard is required. If the drift is high enough it could be detected by comparison with a fresh standard of the same type every few years. Assuming the manufacurer's specifications can be relied upon. Bruce _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
