Dan writes...
>> I can't trust the brake failure lamp...it's lying to
>> me. :-)
>
>No, it's not -- It's just not telling you what you want it too. When you
>first turn on the key, it's telling you that the light bulb works. After the
>engine starts, it's telling you that the brakes have failed if it comes on by
>itself. If it comes on with the oil pressure light, it's telling you you have
>low oil pressure. The burden is on you to know and understand what it's
>telling you.
:-(
> I spent quite a few years designing control rooms for nuclear
>power plants, and I can tell you I could not have gotten by with a
> design like this.
:-)
> We could not place that kind of burden on the operators. Still, I
>think it is a pretty clever design, given the cost constraints. How else
>would you test a light from a switch that never operates in normal use without
>tying it to some other switch, or adding complexity to the design -- time
>delay relays, etc? Look at how MG handled it. They added a costly test
>switch to the dash, and it still requires more participation from the operator
>than the Triumph design.
After Bobby e-mailed us last night I went back and peeked at the
prints for the late model Spits. He was right. They changed the
wiring so that the oil pressure lamp and brake failure lamp are now on
separate circuits. A quick examination suggests that they did this by
adding additional contacts to the ignition switch.
You might think that a small change like this would add perhaps $5 to
the cost of each car but of course life is not so simple. The true
cost was buried in what must have been a substantial investment in
re-design and tooling for the new multifunction directional stalk and
ignition/steering interlock.
It's unfortunate that TR6's were being phased out at this time and
never saw the update. You might not have cared for the "modern"
appearance of the steering column but the ignition switch was much
easier to find and I think you would have preferred wiring scheme.
>A 555 timer is as close as you can get to a universal IC chip. It can be used
>to do just about anything. I am using two of them in the fuel level warning
>system
Snip...
> There is hysteresis built into both circuits, so I should have no problem
>with the
> light flickering around the setpoint.
Yes...this is what I was getting at. My '84 Buick had this feature
but it flickered on and off annoyingly at the set point. Someday I
may ask you for details of your design. <I hope Andy Mace is not
reading this> :-)
> If you get a chance, you need to go to Radio Shack and pick up a booklet
>on this timer. It is an amazing device!
You must be talking about the Forrest Sims booklet. I have a copy
here and at work but that one is hidden. <g>
>I have drawn my schematic on the computer, and I am making an "owners manual"
>for the car, combining all the various inputs from the various venders used,
>so I will have a ready reference later on when I have completely forgotten
>what I did. I have a scanner, so I will copy all the pertinent photos,
>diagrams, etc, that I might need in an emergency, and print them out into a
>glove box sized booklet, along with the wiring diagrams, just like a factory
>manual. The rest of the material I will gather into a folder, and keep in my
>shop. Should my heirs decide to sell the car - I sure won't! -- then the
>manual will go with it.
Wow! You *are* taking this seriously. Actually, I figured this out
already. I visited your website and the images you have there of the
work in progress are very, very impressive. This car is being done
RIGHT!
>No, no! It's all about POWER!!!!!
I thought you were putting a FORD engine in that car? <running,
ducking and logging off really quickly.> :-)
Cheers!
Tom O'Malley in Southbridge Massachusetts
'74, '77 Spits
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