I ran across Microchip’s application note AN220 Watt-Hour Meter (which uses the Cirrus Logic CS5460A Power/Enegry IC) and am interested in using this design for a project. As I am not an EE, I would like to have some advice from those of you who are.

1) As has been pointed out in another thread, Microchip engineers are human and can make mistakes, and on occasion their AN’s can have errors which could be a safety concern. Anyone see any problem’s with this design?

2) My application is a bit different. I am planning on using this design for a 240V (Single-phase – No Neutral Available), 30A application.
a. Based on this, I am most concerned about the current sense transformer T1 being adequate for the application (and what would be a good replacement if necessary, maybe this?).
b. I shouldn’t have any trouble working out the resistor values that need changing. But again, some of you can do this stuff in you sleep, and any help/tips/advice would be welcome.
3) The PIC/Display/Interface part of the circuit where I plan the major changes. Mostly using an 18F series PIC, a 16X2 LCD, serial comm. with PC and/or data-logging on flash/EEPROM. There shouldn’t be any problems with this end. Where I would like the help is on the power supply circuit.
a. I should be able to use the rectified “Vin” (prior to Volt Reg) to power the LCD backlight with appropriate current limiting resistor. Based on a voltage and typical LCD backlight specs, probably a 510ohm/1W resistor should be adequate (possibly 620). Anything wrong with this idea, or a better solution to power the backlight? (I got the idea from reading one of Melanie’s posts a while back, but can’t find it anymore)
b. I’ve seen similar power supply circuits with a diode across the Volt Reg for reverse current protection. Good idea or not needed?
Well, that’s enough to get started. Thanks to anyone that is willing to help.

Steve