(Author: ikom Saturday 4 September 2004 ,
Sep,04,2004Sep,04,2004
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Saturday 4 September 2004
I decided to re-acquaint myself with the loom today - it is getting cold already and I hear the Canada geese overhead. My house is under their flight path and every Spring and fall, I hear them either coming North or leaving for better climes down South. We see big "V" formations above us and this flight traffic continues almost until the end of September. The earlier traffic appears to come from further up North since they are high up - the later traffic is probably local since it is much lower and sometimes they are just circling to make the correct altitude before their migration.
Occasionally several groups will land in the fields across the ravine from me before they assemble into one big group for their flight Southwards. They are an audible and visible precursor of the coming seasons, however, I much prefer their appearance when it signifies the advent of Spring.
I like working on the driveway for this reason and the build dolly is wonderful because it not only allows easy access to the chassis for building the GTR but also makes the whole build very mobile; the driveway literally becomes the extended garage.
The four additional circuits that I am adding take up most of the day since I started late and I have each circuit on a separate relay and each relay has five wires (and so on):
A short description of a relay and its circuits -
"Relays are extremely useful when there is a need to control a large amount of current and/or voltage with a small electrical signal."
"The relay coil which produces the magnetic field may only consume fractions of a watt of power, while the contacts closed or opened by that magnetic field may be able to conduct hundreds of times that amount of power to a load. In effect, a relay acts as a binary (on or off) amplifier."
"The relay's ability to control one electrical signal with another (smaller one) finds useful application in the construction of automobile electrical systems where wiring can be made much smaller to switch large devices."
A simple five pin relay has the following circuits:
85 is the relay switching (control) circuit output.
86 is the relay switching (control) circuit input.
30 is the power circuit input.
87 is the power circuit output.
87a is the power circuit output (always on)
These together with numerous connections to battery and chassis ground etc. constitute a time consuming and headache provoking crimping and soldering exercise. In any case very boring work.
After I complete the wiring connections, I hook up a 12 volt power source and test each circuit and it all works (to my surprise). I will also need to figure out a way of adding a master relay which will be controlled by the ignition switch so the new circuiting will only be alive when the car is on. I decide that I will take care of this at some other time (in the future) since it is late in the day and I have prior plans.
