Re: 2K vs 2.2K - not a problem

[Crash Gordon® <NONE@xxxxxxxx>]

100 ohm loop resistance would be really high doncha think?


"Dave" <google.3.trustme@xxxxxxxxxxxxxxx> wrote in message =
news:1113277621.937550.131320@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> It'll work just fine.  You guys are forgetting that a 2.2k resistor is
> not 2.20000000 ohms.  There is a tolerance in every resistor, and it's
> usually 5 to 10 percent, as indicated by a gold or silver band on the
> resistor.
>=20
> That means the 2.2k resistor that comes with the FBI panel is =
somewhere
> between 2310 ohms and 2090 ohms, if it's a 5% resistor.  The 2.0k
> resistor that comes with the Ademco panel is actually somewhere =
between
> 1900 and 2100 ohms.  See the overlap in values?  Add to that a loop
> resistance of 100 ohms or so, and you can see this stuff is not all
> that precise.
>=20
> If you really want to know for sure, connect a potentiometer across =
the
> zone terminals and see for yourself how high you can dial the pot
> before the zone goes into trouble.  It's probably about 2800 ohms.  =
Not
> a problem.
>=20
> mikey wrote:
> > I'm upgrading my old FBII panel to an Ademco. Ademco want 2K EOL and
> my
> > contacts all have 2.2K resistors in here. Is the Ademco panel going
> to be
> > okay with that? Seems close enough to me tolerance-wise but I'd feel
> better
> > if somebody's done it and all is well. I suppose I could 200R
> resistors in
> > the panel but yuck.
> >=20
> > Thanks
>