oscilloscope input
Hi,
I thought finding the period of a signal is the easiest thing to do; simply AC couple the signal and measure the time between alternate zero crossing points?
In my opinion, if he use comparator, equivalent sampling reconstruction will work proper only if period of input signal >> adc sampling period.
I thought it is the other way around, equivalent Sampling method is mainly used to reproduce high frequency REPETITIVE signals with lower sampling rate, that is, the signal period is much less than the sampling period. What you have mentioned is called Real Time Sampling(RTS) and if the signal wave form is not repetitive, RTS is the only method.
As I understand, in Equivalent sampling method, the consecutive samples are taken at different phases of the wavefrom, from different cycles, and because waveform is repetitive, they can be used to assemble a single cycle as equivalent samples collected from the same cycle. That is why he has mentioned that the sampling frequency should not be multiples of signal frequency,( a very serious limitation indeed), as otherwise one has to generate a sliding random sampling rate, which he is not doing.
As regards project in this area I recommend you to contact M/S Tektronix, who are specialising in this field. For more information on this subject, visit their site
https://www.tek.com. You can also try
www.sourceforge.net for any open source project in this area.
Regards,
Laktronics