Re: I think they've done it again.

[Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Sun, 25 Jun 2006 13:35:31 GMT, "Jeff Volp" <JeffVolp@xxxxxxx> wrote in
message  <Diwng.59175$mF2.27718@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>:

>"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
>news:449e6206.210894546@xxxxxxxxxxxxxxxx
>
>> However, in one post "SmarthomeJohn" says they found it was the triac
>while
>> in another he says they found it was the choke. I would reserve
judgement.
>
>I'm still not clear how this effects dimmers made by other companies.
>
>Jeff


Mike from INSTEON wrote in
http://www.techmall.com/post.asp?method=ReplyQuote&REPLY_ID=636&TOPIC_ID=180&FORUM_ID=9

	"The component that is in question is the choke coil. Repeated
	INSTEON signals generated by the dimmer or controller were getting
	 into the triac and causing the flicker. We have increased the value
	 of the choke coil to attenuate the INSTEON signals that go into the
	 triac. "


There are two inductors in an ICON dimmer with an MCU marked "GL2476D BETA"
with stick-on label. They look just like those on the other model INSTEON
dimmers I have.

The large inductor (choke) is in series with the red AC _input_ lead and
consists in 4 turns of 14AWG on a ~15 mm diameter green toroid and has an
inductance of ~18 uH (measured at 120 hz and 1000hz with an EXTECH LCR
meter). The other terminal of the inductor is connected directly to the
input of the TRIAC.

In contrast, the choke on an X10 WS467 is about 45 turns of ~16 AWG on a
25mm long ferrite rod and measures  44 uH. This construction, size and
inductance is typical of residential dimmers.

"Specification grade" (architectural grade) dimmers have much larger
inductors. This is one of the inherent advantages of centralized dimmers
over wall-mounted dimmers because there is no practical limit to the size of
the inductors in a centralized dimming panel.

(The ICON dimmer also has another, low-current inductor in series with a
diode near the coupling transformer.)

If, as it appears, the problem is with the high-current input choke and can
be solved by doubling the inductance, more turns on the inductor would do
the trick if that doesn't cause the inductor to saturate. But if a
physically larger inductor is needed, space will be a problem. The INSTEON
dimmer cases are/can be made shallower than most other dimmers in part
because the choke is smaller.

Because the response from INSTEON implied (to me at least, reading between
the lines) that an add-on choke might resolve the flicker problem. However
there isn't room for an add-on choke ("Lamp debuzzing coil") such as those
sold by Lutron and others in all but the largest switch boxes.

I have no problems with flickering lights (but did several years ago prior
to installing any INSTEON owing to a inadequately torqued connection to the
neutral/ground  bar in the entrance panel).

... Marc
Marc_F_Hult
www.ECOntrol.org