A-level electonics mode.
Ok all wire has a resistance, the more the ratio of current capacity
to current flowing along a wire, the less the resistance.
When your car is running your altinator/dynomo genereates 14ish
volts, this is connected to the batery, because the batery is
normaly 11.5 volts it's gets charged. So the nerest connections
to the power source is the engin block, and the power output pin.
This is the best grownd in the car, because it skips out the resistance
of the battery / chassy connection.
A resister will limit the current for a given voltage. Thus a 1
ohm resister will give 1amp at 1 volt. 12 ohms will give 1 amp at
12 volts. The resister in paralel with the coil will when connected
devide the coil voltage, coil has a resistance, and so does the
resister. This devides the voltage in the middel to half way between.
A perfect capacitor esential has infinite resistance to DC, and a
varying finite resistance to AC getting lower as the frequency gets
higher. Thus when placed accorss a power line it shorts intabilitys
to earth whilst keeping the DC potential in the lines sperat.
A capaciter is an insulator with two plates ether side, hence the
simble is -| |-
How to make your car more immune to noise.
1. Capaciter from points to ground.
2. Capaciter from coil + to ground, its on the same wire, but the other
end
this is because a wire is a resister and all that.
3. Capaciter from Altinator /Dynomo + to grownd.
4. A capaciter from windsceen wiper moter +'s to grownd.
5. A capaciter accross the coils of relays, work like the coil in the
ign.
6. Make shure that the HT leads do not run in parrelel to the other wise
it
acts like a capaciter and lets AC through, and you get all the noise
from
the ign.
7. A capaciter from your radio + to radio ground, one on the arial
input,
NOT speaker out you want that AC, and + for any amps.
I think this type of capaciter should be a 20 volt electolitic 16uF,
purchaced very expencivly from an auto parts store, or if you can
cope with the differnt case very cheaply from an electonics store.
Next week how to build a micro processor contoled electronic
management system.;-) (What you don't beleave me?)
--
James Carpenter
Yellow '79 spit wired by a trained marmot
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