California, Europe, much of Asia and other regions have mandated efficiency standards for wall transformers that can currently be met only by switched-mode power supplies (SMPS). Early SMPS designs were noisy and could cause problems for X-10 and Insteon either through putting noise (in the 100-150kHz range) on the powerline or by using line-filters that attenuated frequencies in this band.

I have tested the +5V version of SMPS sold by Circuit Specialists and found them to be X-10 & Insteon friendly. My ESM1 shows no noise nor any attenuation of X-10 signals. I can see no noise on my DSO (digital sampling oscilloscope).

I measured the idle power usage using my Kill-A-Watt meter using the kWh mode with no load on the power supply to measure its energy usage when unloaded. It registered 0.01kWh sometime between 61 & 68 hours. This means when unloaded it uses less than 0.2W or less than 1.5kWh in a year for an approximate cost of $0.08 annually. At current rates it would cost about twice that much in California. The Power Factor is 0.3.

I have also tested a +5V SMPS from ETA-USA sold by Mouser Electronics (PN 618-WCS10-05SX) and found it to be X-10 & Insteon friendly. When idle it wastes about 4 times as much power as the one above. The Power Factor is 0.3.

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