I am in the process of building a isolation power conditioner for my
home theater set-up. I would like to have some of the outlets
switched based on the 12 v trigger from Integra 9.1 receiver.

Does any one know what the current source capability of this trigger
is?

I was considering using it to drive a 12v relay. The 12-volt relay
would then switch 115v, which in turn would feed into a 115v relay
with 20 amp contacts. The reason to cascade the two relays is that I
suspect that the 12 v trigger can only source small amounts of current
and I suspect that a 12 v relay with 110 contacts would require quite
a bit of current.

I am also thinking of adding a small RC circuit with a 2 or 3 second
time constant (on the 12 v line) to delay the turn on of the other
outlets.

Any thoughts on this would help.

regards,
Doug

In article ,
(Doug Fraser) wrote:

I am in the process of building a isolation power conditioner for my
home theater set-up. I would like to have some of the outlets
switched based on the 12 v trigger from Integra 9.1 receiver.

Does any one know what the current source capability of this trigger
is?

I was considering using it to drive a 12v relay. The 12-volt relay
would then switch 115v, which in turn would feed into a 115v relay
with 20 amp contacts. The reason to cascade the two relays is that I
suspect that the 12 v trigger can only source small amounts of current
and I suspect that a 12 v relay with 110 contacts would require quite
a bit of current.

I am also thinking of adding a small RC circuit with a 2 or 3 second
time constant (on the 12 v line) to delay the turn on of the other
outlets.

Any thoughts on this would help.

regards,
Doug

The 12V line should have no problem driving a power relay directly. The
receiver specs should show the current ability.

The need for an isolation power conditioner sounds pretty messed up.
Either you have something very wrong with your equipment or somebody is
selling you snake oil.

Doug Fraser wrote:

I am in the process of building a isolation power conditioner for my
home theater set-up. I would like to have some of the outlets
switched based on the 12 v trigger from Integra 9.1 receiver.

(snip)

No quite sure what you are doing but it looks like you want
to power up the main system via the isolation unit when a
small receiver goes on.

I did something like this in my system. The twin passive
sub-woofer amplifier (a Yamaha M4) took too much power for
the switched AC outlet on the receiver so I used this 120
VAC to close a power relay (120 VAC coil) that switched the
M4 on. The contacts were all rated at over 10 amps, IIRC,
but I wired a pair in parallel just to be sure. I forget
the part number but the relay was a common industrial type
that cost CDN$22.00 a couple of years ago.

Of course, it requires the receiver to have a switched AC
outlet.

I am also thinking of adding a small RC circuit with a 2 or 3 second
time constant (on the 12 v line) to delay the turn on of the other
outlets.

Not sure why you would want to do this - unless I've misread
the project objectives.


Any thoughts on this would help.

regards,
Doug

Cheers,

Roger
--
Roger Jones, P.Eng.
Thornhill, Ontario,
Canada.

"Friends don't let friends vote Liberal"

Guys,

Thanks for the replies.

To address a few questions that have been raised....

The reason for the time delay is that I would like to power up my
subwoofer amp (Crown K2) last. I have a parametric EQ between the
Surround Sound Processor and the Sub amp. The idea is to avoid turn
on thumps.

With respect to the bill of goods.... I have not been sold a bill of
goods. I don't believe that I will hear any difference with or with
out the isolation. I am doing it for one reason. I am an EE and this
is my hobby. I also have a hum in my sub and believe me, I have tried
almost every thing to figure out where it is coming from. I have
isolators on the cable TV inputs (for FM and cable to the TV - I have
a composite video connection from the Surround Sound Processor to the
TV). I am using Rane's Balance Buddies to for isolation and level
conversion (consumer to pro levels) on the sub line to the parametric
EQ and then on to the Crown K2. I have plugged every thing into a
single 20 amp cct with a dedicated ground to the distribution panel.
I now want to play and see what an isolation transformer buys me.

I also am adding transient supression into the power conditioner.
While I have never had a problem with transients - remember it's my
hobby.

Doug