X-10 Mods

X-10 Mods

Using an Auto-transformer

For those USA X-10 units that take little current it may be possible to operate them from a 230V to 115V auto-transformer. The autotransformer presents a high impedance to the X-10 signals and so it would normally prevent the X-10 signal from passing. However, if a 0.47 microfarad capacitor is placed across the 230V and 115V windings, this allows the X-10 signals to pass backwards and forwards through the auto-transformer. If the capacitor is placed across the 0V and 115V windings, then it will further attenuate the X-10 signals and make absolutely certain the X-10 device will not work.

The capacitor must be rated at least 250V AC or 600V DC, and fitting it will usually require that the autotransformer be disassembled, so care must be used.

I have successfully used this technique to get the 115V USA CM15 to operate in the UK.

Reference

The most complete details of 115 volt to 230 volt modifications were on Hans Attersjö's home page but this has now closed. I have taken some of Hans's work and loaded it onto my server together with corrections identified by readers of these pages and myself; I have also included my own modification instructions. The circuit diagrams are courtesy of Steve Bloom.

Modification Reference

The table below gives links to Modification Instructions, Circuit Diagrams and indicators to modules that I have successfully modified. Links are in the Instr and I Mod columns.

X-10 Modification Reference Table

Links are in the Instr column to the modification instructions.

Part #
Description
Instr
CirDiag
I Mod
Oth
All
General Modification Principles
N/A
N/A
-
AM 486
Appliance Module
-
-
SC 546
Chime Module
Yes
-
CP290
Computer Interface
-
-
-
-
IBM Home Director
-
-
-
-
JDS Time Controller Plus
-
-
-
LM465
Lamp Module
-
-
-
SC503
Maxi Controller
-
Yes
-
MEGA32
Mega Controller
-
-
-
MC460
Mini Controller
-
-
-
MS12A
Motion Detector
N/A
-
-
PF284
Power Flash
-
Yes
-
TW523
Power Line Interface
-
-
-
SR731
RF Repeater
-
-
-
RR501
RF Transceiver
-
Yes
-
TM751
RF Transceiver
-
Yes
-
360-3158
Stanley Motion Detector  
Yes
-
WS 467
Wall Switch
-
-

 Key

  • Instr: Link to Modification Information (will open in a new window)
  • CirDiag: Link to Circuit Diagrams (will open in a new window)
  • I Mod: If Yes, means I have successfully modified the unit.
  • Oth: If Yes, means others have reported success; if No, means others have reported failure

Sourcing of Components

Generally the parts can be sourced from Maplin Electronics. The one microfarad 250V AC is particularly hard to find as it must be rated at 250V AC minimum. If a 250V DC capacitor is used instead, it will explode. Capacitors are usually rated with a DC voltage and so a 600V DC one should ideally be used. However, these larger capacitors may sometimes be too large to replace the original components.

The Voltage dependant Resistors (VDRs) are also known as Varistors; they present a high resistance at normal voltages but a very low resistance to high voltages and so these are used for surge suppression in the X-10 modules. If you forget to replace the 150V VDRs, they too will explode when connected to 230V.

Your Turn Now

If you have any success or failure, or any comments to make on these web pages then please let me have details and I will incorporate them into this reference library.