However, when is not fed by batteries, the LED is always ON, making the detection circuit useless. I tried back again with the AAA batteries and it works fine!Am I missing something here? Any idea why is working with batteries and why is not working with a wired power supply?
Quote from: joaoabs on Jun 13, 2013, 01:36 amHowever, when is not fed by batteries, the LED is always ON, making the detection circuit useless. I tried back again with the AAA batteries and it works fine!Am I missing something here? Any idea why is working with batteries and why is not working with a wired power supply?Use optocoupler to replace LED, this will be isolated between. Use isolated dc supply or wireless power module to power up the board. Use decouple cap at 3 V power. put small cap at input of IC for low pass filter.
QuoteYou could probably eliminate three of the diodes because half-way rectification would be adequate in this case.Yes we could, all we need add one electronic capacitor at output half-way rectification.or use thissince we face 24V instead of 110V, cap could be droped.second one use Optocoupler with AC Input.
You could probably eliminate three of the diodes because half-way rectification would be adequate in this case.
Do a search on ebay for Arduino Current Sensor. I was actually just looking for Arduino stuff and saw the current sensor modules. I thought about getting this one:http://www.ebay.com/itm/5A-20A-30A-Bi-Directional-AC-DC-Current-Sensor-Module-arduino-compatible-/111085883206?pt=LH_DefaultDomain_0&var=&hash=item19dd3c0f46Michael
I used some ACS712 kits connected to a PCF8591 (I was planning to know if the appliances were on/off by reading the value on each ADC port). There are kits of 5, 10 and 20A. I tested a 5A kit, the datasheet says it will increase 185mv per Ampere. The appliance I tested is a 20w Led floodlight and therefore consumes around 90mA (220v AC). This means the ACS712 would increase 16mV when ON, which is difficult for the PCF8591 to notice any difference (8 bits). Also, since my appliances are AC, the output of the ACS712 is also variable (50 Hz).So I gave up of detecting if the circuit is closed by current sensors, and I believe I need to approach this problem differently. Basically I need a circuit that detects that the appliance circuit is closed (relay and internal switches) and then puts a digital pin at "1". I saw some ideas in the web with phototransistors, like the TLP620, but I'm not sure it could support voltages like 220V AC. Any suggestion? Thanks,Joaoabs
There are a lot ways detect AC, but OP's way is the most coolest way.