220V Mains Monitor

							220V Mains Monitor
Description:
  With this circuit you will be able to monitor the quality of the mains.
  There are 4 distinct sections, each supervising a parameter
  pertinent to the quality of the supply line. The noise section consists
  of a 50Hz filter and a speaker where you will hear the noise present
  on the line. The bicolor LED should be adjusted for the least light
  with the 5k pot and gives a visual indication of noise or asymmetry
  in the wave.
    The second section will detect any spike which is overimposed on
  the mains voltage: adjust the pot so that it will not trip if you just
  switch on the light, sensitivity is high enough to detect a switching
  operation from a close neighbor. The buzzer will beep for about
  1sec anytime there is a spike. The actual voltage is detected with
  section 3: the yellow led will blink at a rate of 6 Hz but will visibly
  double to 12 Hz for a 10% increase or will come to a halt for a 10%
  decrease of the voltage. The last section will show the flutter or
  slow variations of the mains voltage. The circuit will work for a 220V
  mains: for 230V operation, change the 27V zener to 39V and for
  60Hz operation change the 3.9k resistor to 3.3k and the 47k resistor
  to 39k. Operation at 110V will call for a major redesign of the
  component values and has not been attempted