>
> Thanks a lot! Just when I begin to understand the "smoke" concept, people
> start talking about relays!
>
> Would some kind soul who understands electrons and their interaction with the
> "smoke" concept kindly draw out in ascii graphics a simple non-relay, and a
> simple relay circuit?
>
> I'd also really appreciate a short discussion of the innards of a relay.
>
> Thanks in advance,
>
> Sean "electrically challenged" Johnson
> '79 MGB
> '75 Spitfire
>
The following bad ASCII art will hopefully help the even lamer explanation.
Un-Energized Relay:
____________________________________________
| |
| Contacts |
| \_/-------------------------| |
| | |
| /-\______________ | |
| |) | | |
| (| | | |
| |) C | | |
| (| O | | |
| |) I | | |
| (| L | | |
| |) | | |
| (| | | |
| |) | | |
| (| | | |
|__||_______________|__________|___________|
|| | |
SW||GND BATT| |CIRCUIT
Low Current High Current
Wiring Wiring
Energized Relay:
____________________________________________
| |
| Contacts |
| _____________/-----------| |
| \_/ | |
| /-\______________ | |
| |) | | |
| (| | | |
| |) C | | |
| (| O | | |
| |) I | | |
| (| L | | |
| |) | | |
| (| | | |
| |) | | |
| (| | | |
|__||_______________|__________|___________|
|| | |
SW||GND BATT| |CIRCUIT
Low Current High Current
Wiring Wiring
A relay basically is just a remotely controlled smoke switch. It is
used in applications where a large amount of smoke needs to be switched
on and off. Inside is a switch that is controlled by an electo-magnet.
As you remember from physics, an electro-magnet is a coil of wire
around an iron bar. It is designed with small wire so that when the
user puts smoke thru the coil wires only a small amount is needed to
produce a large enough magnetic field to pull the contacts together
(someone else needs to explain the effects of smoke and magnetic
fields). The contacts are designed to pass a large amount of smoke.
This way a small switch on the dash with small wires can control large
amounts of smoke elsewhere. This is the principle behind the ignition
switch and the starter solenoid (another name for a relay). As with any
switch when the contacts open or close a small amount of smoke escapes
from the wiring and makes the contacts dirty. This accumulates on the
contacts over a period of time rendering the relay us
I hope this basic explanation is clear. I hope others more well versed
will embellish this with a more astute answer.
Comments Welcome!!
- -Mark
|