Energy Harvesting Circuit - an interesting approach

Greetings Everyone,
I found a Guest article by Pierre Mars, VP Applications Engineering, CAP-XX (Australia) Pty Ltd. It has a very interesting circuit in Fig 9. I am attempting to build circuit shown in Fig. 9 although I am using equivalent chips for comparators and op amplifier (all dip the chips mentioned in article are not dip). Unfortunately, the image of fig 9 cannot be magnified therefore I have to estimate values. I would appreciate anyone with sharp eyes and experience about Ref voltage for comparators. What it is and how do I create one? Note that the only source of power for the entire circuit is from the coil. Is it ground or Vdd based on my choosing?

https://www.energyharvestingjournal...ercapacitor-to-manage-your-power-00001921.asp

The only values given are 2.2M on the charge balancing circuit at the right side. The values must be equal but the exact resistance isn't very important. Higher values will drain less current but make the circuit more prone to input leakage in the IC. 2.2M is a good compromise value.

The other resistors depend entirely on the voltages you get from the generator. The reference is measured from the negative rail. The potential dividers on the reference voltage and the measured voltages decide at which point the comparator switches so in theory you can use any reference you like as long as the ratio of resistors is set appropriately. I'm not sure the schematic is supposed to be regarded as a construction project, I think it more likely to be an example of how such a circuit could be used.

Brian.