Modyifying the Stanley Motion Detector

Introduction

I have successfully modified four Stanley Motion Detector units and developed these instructions at the time (modifications on one unit failed).  I would like to emphasise that I have not traced out the full circuit diagram to determine whether or not these modifications are correct.   You follow these instructions at your own risk.

I have also now successfully modified an X-10 equivalent unit that looks different, but which is electrically identical.

Modification Steps

  1. First disconnect the unit from mains power.
  2. Undo the knurled knob at the bottom of the unit and swing out the cover; you may find it easier to remove the cover.
  3. Remove the four screws in the corners of the facia.
  4. Pull out the electronics from the case, easing the wires back into the case.
  5. Remove the top circuit board by unscrewing the four screws in the corners.  These screws are live with mains power applied.
  6. I decided not to let the unit switch lights through the internal relay so unsolder the blue wire and one of the white wires.  You must do this otherwise the relay coil will catch fire.
  7. Remember that the live wire is black (brown in the UK, or red on old wiring), and the neutral wire is white (blue in the UK, or black on old wiring).  So be careful.
  8. Locate C25, the 2.2uf 250V capacitor and replace it with a 1uf 400V capacitor.  You will need to remove the white epoxy glue around both capacitors; a small pair of pliers and cutters can do this easily.
  9. Locate C16 the 220nF 250V capacitor and replace it with a 100nF 400V capacitor.  Be very careful when you solder the replacement capacitor in as the circuit board tracks are very close together.
  10. Locate R50 the 22 ohm 0.5W resistor; unsolder one end, and add another 22 ohm 0.5W resistor in series.
  11. Unsolder the two wires that go to the relay coil at the circuit board end.  Ensure the loose wires cannot touch the circuit board by taping them up.
  12. Change VDR1 from 140V to 270V.  You do not need to change the second VDR if you disconnect the wires from the relay.
  13. Locate R51 the 330k ohm 0.5W resistor; and replace it with a 560k ohm 0.5W resistor.
  14. Make sure there is no stray solder on the circuit board and check your work carefully.
  15. Reassemble the unit and put a 2 Amp fuse in the plug on the power lead and plug it into the mains.  Be careful that you have the blue potentiometer knobs in the right quadrant.
  16. Test the operation of the unit as per the Stanley instructions.

If you attempt these modifications, please let me know your results, and read the warning on the X-10 240 volt modifications  page.

Comments received at Redoak

None so far.


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