[RFI] Mobile amps and vehicle issues

[Jim Brown]

On Wed, 11 Jan 2006 13:08:07 -0500, FoMoCo EMC wrote:

>Susceptible circuitry is rampant in a vehicle.  Almost every electric motor 
>in a vehicle is speed controlled by a pulse width modulated signal.  A 
>little bit of RF into the circuit and the motor will exhibit undesired RPM 
>variations.  There are a dozen sensors on the engine and throughout the 
>vehicle that put out low level signals that can be disrupted.  Imagine what 
>occurs when the vehicle can no longer tell if tire rotation is occuring 
>(wheel speed sensors) or can't determine the postion of the camshaft, 
>crankshaft, or throttle plate.

Of course. But there is no excuse for poor wiring practices, or for not bonding 
the body, for omitting ferrites at sensitive points in the circuit, or for 
designing those very complex systems with pin 1 problems. 

Jim Brown K9YC