I am trying to make a circuit that can detect if a light (120v 60watt) is on or off, seem simple but I'm lost. To do this I have an CTS306-1a (http://www.mouser.com/ds/2/410/CST306-1A-222452.pdf). I am feeding that into a diode bridge to convert it from AC to DC, then to and op-amp, then to an arduino. I have not gotten it working; yet. I'd appreciate it you can point me in the right direction. I think i might have A) things in the wrong order B) missing some bits C) all of the above and then some.
I drew up a schematic of what I thought would work. I'm sure its hysterical!
That is not a standard CT. If you look at the spec sheet you will see it is designed to operate in the frequency range 20kHz to 200khz. Mains frequency is 50Hz or 60Hz (depends where you live). So you need to get hold of either a CT to operate at this lower frequency, or better still a hall sensor that outputs in the range 0-5volts. If you do decide to go for a CT you will need a burden resistor across its output terminals otherwise it will produce excessive voltage as it endeavours to output the specified current ratio. See the attached http://openenergymonitor.org/emon/buildingblocks/ct-sensors-interface
I think that is overkill. I would point a phototransistor at the light and read the state of the line.
Might need a pull down resistor. I don't know these things.
Jack, thanks , I never spotted that issue. I have another ct that reads 5.3 MV when a 100watts is on. However I think I will get some ACS712 boards, as it looks like it will do most of the work for me.
Bigred, yeah, I have considered this. It will need to work well in an environment with a ton of lighting sources (tv studio), so its not a good option for me.
Thank you both.