Wiring 2 Pyro's to 1 guage!

[zman]

Besides Radio Shack, are there any other good sources for DPDT switches? I have the need to install a couple other SPST switches and I would like for all of my switches to have the same look. My preference is a fairly small, lighted, rocker switch. Thanks!

Steve

 

[illflem]

zman, Radio Shack has a great assortment of switches, until you get in to 12 volt DC lighted ones. You are then better off going to automotive sources, Summit, JC Whitney, Carparts.com or a larger auto parts store are a good place to start.

 

[radixr]

Radio Shack has a good selection of 12v, lighted switches on their website. That's where I got mine. It could be tough to match a DPDT rocker and SPST lighted rocker switches.

 

[Cooker]

I agree the Radio Shack website has a good selection of many things the store or the catalog doesn't have.

 

[zman]

I've looked high and low for a 12vdc DPDT rocker switch (preferably lighted) and can't find one anywhere. Does anyone have a part number/source for one? I've checked online at Radio Shack and the other places listed above and have come up with zip. All help appreciated. Thanks.

Steve

 

[Steve St.Laurent]

How about the other way around? I need to run two gauges off of one thermocouple - one is an actual analog gauge and the other feeds the EGT to the Powermax for defueling based on EGT. When I installed my Isspro turbo temp monitor they said to daisy chain it off of an existing gauge to run copper wires to the existing gauge so the two gauges are in parallel. Other's have recommended using two thermocouple leads from the thermocouple to each gauge (also in parallel but two seperate leads connected to the same thermocouple instead of running copper wires to the second gauge from the first). Any thoughts?

-Steve

 

[illflem]

Steve, I would think that as long as the Isspro unit isn't too far from the gauge that you could just connect the Isspro up to the back of the gauge. If doing it this way affects your pyro reading you should be able to tell even at an idle by connecting the Isspro while running with your eye on the gauge.

 

[Rambling]

Steve, based on some recent experimenting with a two digital guages, copper wires, a terminal block, several K-type thermocouples and thermocouple inter connect wire, I would suggest using thermocouple wire and not the copper between the two instruments.

I used copper wire between meter(1) and the T-block and connected a thermocouple connected on the opposite side of the terminal block. Meter(2) had a K-type thermocouple connected directly to the the meter. Both units read within 1 degree of the ambient temperature. When I measured a known temperature (98. 6) meter(1) read about 106 degrees while meter(2), the control, read 97. 8. When I replaced the copper wire between the meter and the T-block, both meters again read within 1 degree of each other at both known temperature measurement points.

I'm sorry that I don't have enough data determine if this is progressive with temperature (66 to 98 = 8 degree error therefore 66 to 366 = 80 degree error?).

The T-block was to allow switching between two thermocouples using copper wire between the T-block and the switch. Only one side of each thermocouple needs to be switched. The other side (obviously needs to be the same side) is daisy chained to the terminal to the meter.

Copper wire was used only for jumpering and runs to the switch.

[This message has been edited by Rattlin (edited 04-07-2001). ]

 

[Cooker]

Here is some additional info on this topic:
"The only thing that matters is that you
use the thermocouple wire that came with
the thermocouple in a lenght long enough
to get it out of the engine compartment
(or at least away from the heat). Once you're away from the engine, any kind of wire (18 gauge)will work okay. "

and

"The special lead wire from the thermocouple is type "K" and must be used until outside the engine compartment. The special cable can be shortened with this gauge since it is an electronic unit and once outside the hot engine room you can continue using standard 18 awg copper wire. "

This is from two different sources, so I feel confident the info is accurate. Also I was asking about the VDO pyrometer becasue that is what I have, but I would imagine it applies to any electronic pyrometer.

Ryan

 

[Rambling]

I edited my previous post to hopefully inprove clarity in the setup and results. The experiment was in preperation for a digital meter installation. #ad
Just thought I'd pass on some data that I obtained. It does support Bill's take on the subject.

Make of it what you will. #ad
You're milage may vary depending on you're installation. #ad




[This message has been edited by Rattlin (edited 04-07-2001). ]