Re: mystery signal

[Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Fri, 11 Nov 2005 19:53:30 GMT, Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>
wrote in message  <9up9n1l000bvuf3mhbrgq14p2r73h2f54o@xxxxxxx>:

>But back to the question:
>
>Unlike the ubiquitous TRIAC-based lighting dimmers that turn the AC off
>during the AC cycle and are turned back on again only at the zero-crossing,
>dimmers based on IGBT (Insulated Gate Bipolar Transistors)  devices can
>turn the AC on *and* off during the cycle, not just at zero crossing. IGBT
>dimmers are becoming more prevalent.
>
>As best I know, there is no reason why a manufacturer of a dimmer has to
>avoid 120khz (X-10) or 130khz (INSTEON) when choosing a frequency to
>control ("dim") an IGBT. And 120khz _is_ the maximum frequency reported for
>some popular IGBT devices.
>
>So Dave's new-found dependability may be from a newer, IGBT-based dimmer
>running at about 120khz for light dimming or motor control. Doesn't bode
>well for PLC in general.


or a sine-wave UPS
http://www.tripplite.com/products/product.cfm?productID=2934
http://www.powerware.com/EMEA/UPS/9355_UPS.asp

or a

Washing Machine
Air Conditioner
HVAC (Compressors, Blowers, Pumps)
Refrigerator
Small Motor Control
Traction Inverter
UPS Power Supply
Servo Drive
Medical Power Supply
Motor Drives
Inverter
Welding

etc  http://www.pwrx.com/igbt.asp?catid=50

Lotsa new stuff potentially adding to the powerline cacophony.

... Marc
Marc_F_Hult