- on Home & Garden
- Published in issue 7/2003 on page 0
Seconds and Minutes Clocks from DCF77
Nowadays, the availability of inexpensive receiver components makes it attractive to use the DCF77 signal at 77.5 kHz (transmitted from Mainflingen, Germany) for trivial applications. The circuit shown in Figure 1 can relatively easily extract seconds and minutes clocks from the DCF77 signal. As is well known, the 59th second pulse is missing every minute in the DCF77 signal, with the missing pulse marking the minute. To obtain an uninterrupted seconds clock, we must first generate minutes pulses from these gaps and then derive the missing seconds pulses from the minutes clock.