guys i have a stove/hob which has inbuilt circuitry to auto ignite the flame, basically it has a spark plug which are powered by 2x1.5v batteries!!...
i want to be able to read on arduino when the circuit is closed ie spark is being generated, i tried to attack the -ve pin of battery to ground and +ve of batter to analog pin and tried to read values, but due to very high voltages generated the PC which arduino was connected to was restarting when i activated the spark circuit!!
so is there any way to read such a high voltage safely ??? or is there any simple device which i can make to measure if current is flowing?
Don't you have the possibility to get the signal before the high voltage transformation occurs? If the power source is 3V I guess the main circuitry is in 3V or 5V and the high voltage part is just the last stage. If you're able to get that signal you probably can process it with Arduino onboard devices.
The sparker will create lots of electrical noise and may not be readily screened. Filter the signal with a capacitor near the Arduino input. Say 0.1uF ceramic. You could look at an opto-coupler which is just an LED and photo-transistor packaged together. They give voltage isolation which can help. Lots of these around, 4N28 comes to mind.
so how do i connect it the capacitor?? to the ground and analog pin which i am taking reading from?? or in series to the analog pin??
if this doesnot work maybe ill try getting optocoupler which is difficult to find here, and will it be able to handle such high voltages of more than 1k volts? coz my dmm which had max rating ok 1k volts is not working when i measured the voltage across the battery when the igniton was on i think it got fried