Hello i have a pretty basic questions but i do not know how to search for a solution.
The circuit is basically a reference crystal with a high frequency that gets divided and then decade counters just count up ms , seconds , minutes , hours , etc. The data gets fed to CD4543 BCD decoder ics that are connected to 7 segment displays for output.
Problem is that when the power goes out i want the oscillator and the crystals keep going with the help of a battery and have the decoder ics and 7 segment displays shut down.
First questions is : Would a comparator circuit work for this aplication ?
2) Can it operate fast enough so the circuit does not lose track of counting
3) Will there be a problem in controlling the power delivery of the 7 segment displays and the decoders through a mosfet.
Thank you. (if you need more information i would be more than happy to provide it)