pc controlled ac devices

[tul]

please help me how to build a circuit that will indicate whether an ac device is on or off????the output of the cicuit is 5v dc so that i can use it as an input for my program...ive got an idea to use a transformer in series with the ac device and use it to activate a circuit that will send a 5v dc signal whenever an ac device is turned on..but it might affect the voltage and current coming into the ac device itself and also its impractical if i have plenty of device to check whether its on or off.........
thanks...................

 

[mvs sarma]

Hi
perhaps in the so called AC device, you can an opto isolator to help convert its ON / OFF condtion.

accordinly you can perhaps use the transister portion by wiring up to your PC monitoring , this transistor can be powered by the PC . if it is ON the device is ON and vice versa.

 

[Hero999]

Use an opto-coupler with the LED powerd from a mains LED circuit and the photo transistor side connected to a pullup resistor on the 5V side.

 

[tul]

thanks a lot.....can i ask sumthing again...are u familiar with celphone to computer comunication using vb??hehehe tnx..........

 

[tul]

thanks a lot...it really helpd me..can i askyou sumthing again???are you familiar with celphone to computer communication using vb???heheh thnks....

 

[Hero999]

No. ..........................