hakan said:my major problem is the noise of power suply. some times it gets noise form another component like a selenoid near it. At that time my microcontroler resets itself. i need to avoid noise from other components like power switchs.
can u advice me a passive filtering method?
[/i]2000 said:hello pal,
I'm having exactly the same problem, in my project I drive 4 relays using an uln2003 darlington driver and this relays drive 127V to the controls of a motor. The noise makes the uc to reset and generates undesirable interruptions like buttons ints. Is it due to the noise in the power line? I'm using this dam 7805 and a 100uF eletrolitic cap in its input/output.... my reset ckt is a simple 10uF cap and 8k2 resistor... what could be done to make it "noise proof"???
There are many good suggestions that have been submitted. The 127 motor coil can cause allot of problems. If you take a .1uF/600wvdc and a 100 ohm resitor in series with the cap. Then place this "snubber" accross the load it may help. For you application I have used Opto isolators. These 6 pin devices isolate the drive circuit and the dirty outside world noise