Lamp Module turned into a Silent Appliance module  for a Buck!

Credits: Original page by Jim Bell

 

Actually the cost may be a little over $1.00, depending where you get the parts. The parts list and costs are:

Part Description Cost & Supplier
MOC3042 Opto Isolator $0.78 (10 for $7.78) from DigiKey
22 mfd 25v capacitor $0.14 (10 for $1.40) from All Electronics
1000 ohm 1/4w resistor $0.0 removed & re-used
22 ohm 1/2w resistor $0.05 (10 for $0.50) from All Electronics
     
Total   $1.01

Disclaimer
These article documents modifications to the X-10 LM-465 Lamp Module. Opening these modules will void your warranty. And more importantly, removing these modules from their cases will expose you to the possibility of electrocution. The modules connect DIRECTLY to the line voltage (120 Volts). When there are out of their protective plastic cases, they can kill you if connected to the wall socket and you touch the wrong thing. Do NOT connect these modules to the wall when out of their cases! Be very careful! Also, there is a possibility of the module catching fire if wired incorrectly and plugged in. Proceed at you own Risk! I take no responsibility if you electrocute yourself or cause a fire.

  • I used 24 gage hook-up wire for this project, unless otherwise indicated. I found that anything bigger would not fit in the smaller holes in the PC board.
  • Remove the 2 phillips screws from the Lamp module unit.
  • Lift the end with the 2 pins up slightly. The other end (with the receptacle is held together with 2 plastic tabs. Insets a small, thin-blade screwdriver into the little slots and twist. The case will snap open. See following photo for detail.
  • Once you get the case slightly apart on both ends, remove the front part and put in a safe place so that you will not bump it and disturb the dials. They can be a little difficult to get back in. Remove the module from the rear part of the case.

 
  • Remove the screw, washer, and nut holding the heat sink to the triac.
     
  • Unsolder the choke from the PC board. Remove the choke from the heatsink.
     
  • Remove the resistor R5(1K) and save. Remove resistors R10(39 ohm), R3 (100k) and R6 (330K). Remove diodes D7, D8, D9, D10, D11. Remove transistor TR1. This isolates the gate of the triac and the collector of the gate driver transistor. See following photo
The module now looks like this:
We are going to hotmelt glue the MOC3042 to the PC board. The glue does not stick very well to the slick surface of the board. Use a small piece of medium sandpaper to remove the gloss right above the existing IC. Also install a jumper (I used 20 guage stranded wire) into the holes formerly occupied by the choke.
We now hotmelt glue the MOC3042 to the PC board right above the existing IC. Be sure and orient pin 1 as show in the following photo.
Now we are ready to begin the wiring of the MOC3042. Since there are no extra holes in the PC board that we can use for the 1k resistor and the 22mfd cap, we have to mount them on the MOC3042. Start by cutting the leads of the cap to about 3/4 in. Make a small loop at the end of the negative lead and attach it to Pin 2 of the MOC3042. Take the saved 1k resistor, make a loop in one end and attach it to Pin 1 of the MOC3042. Now take the free lead from the cap and the free lead from the resistor and solder together. Looks like the following photo.
Now run a wire from the junction of the 22 mfd cap and the 1k resistor to the hole of the original TR1 nearest the edge of the board. This connection picks up the +15v source. Run a wire from Pin 2 of the optoisolator to the right hand side of the hole formerly occupied by R10.
 
Install a 22 ohm resistor in the hole formerly occupied by R3. Use the
left hand hole.

 Connect the other end of the resistor to pin 6 of the MOC3042. This connects the output side of the optoisolator to the line.

Connect one end of a wire to pin 4 of the optoisolator. Connect the other end to the formerly occupied left hand hole of D11. This connects the optoisolator to the gate of the triac.

 
Now take the heatsink and modify it by cutting off the part shown in the following photo. I used diagonal cutters. We need to do this because the new wiring is in the way of the tab.

 

Install the heatsink back to the triac with the saved screw, washer, and nut. Tighten securely.

Take the back section of the case and insert the module back into it. Be sure that no wires are caught.

Take the front case part and hold it with the front down. Take the module with the back case and push it onto the front case part. The part of the case that you pried apart will have to be snapped back together. It takes some pressure with the fingers to do this.

Install the 2 phillips screws.

We are Done!

The original wattage rating on the label is 300 watts (approximately 2.5 amps). Although the circuit itself will handle more current, the heatsink will not. So stay within the 300 watt limit.

Old Circuit
New Circuit