AC voltage monitoring using arduino

[srx87]

Hi. i'm in the process making a monitoring 240 ac voltage system using arduino. the examples that i working on based on this website: http://openenergymonitor.org/emon/node/58

one thing that i notice is that, they using an AC to AC adapter. so my question is:
1. how to get the ac/ac adapter?? i try to google it, but zero find.
2. is there any chance that any other ways to measure 240 ac voltage?

thanks in advance.

[ABSF]

1. how to get the ac/ac adapter?? i try to google it, but zero find.

Voltage sensing electronics:
1x 9V AC-AC Power Adapter
1x 100kOhm resistor for step down voltage divider.
1x 10kOhm resistor for step down voltage divider.
2x 10kOhm resistors for biasing voltage divider (or any equall valued resistor pair upto 470kOhm)
1x 10uF capacitor

Current sensing electronics
1x CT sensor SCT-013-000
1x Burden resistor 18 Ohms if supply voltage is 3.3V or 33 Ohms if supply voltage is 5V.
2x 10kOhm resistors (or any equall valued resistor pair upto 470kOhm)
1x 10uF capacitor

By AC/AC adaptor I think he meant a power line to 9V step down transformer. ie 240:9V transformer...

Allen

[srx87]

Thanks for the reply. so it means step down the 240v ac to 9v ac using transformer.



but can we directly fed AC power to arduino pin?? i never play with ac before.

thanks..