Voltage regulator

[Greg Hermann]

>
>It's good to know shunt/ series motor theory.  Though it's full effect is lost
>on the original app discussed ( running a OEM fuel pump at a < or > voltage)
>Most if not all OEM intank or external pumps are permanent magnet style.  The
>Holley Blue or Red pump may have field coils as well as some other aftermarket
>pumps.
>
>As for running a pump at reduced voltage.  The ~85 Merkur XR4Ti 2.3 Turbo (
>same engine as a SVO Mustang) uses a resistor wire simillar to a ignition
>resistor.  The ~ 86 Reanult Alliance ( ala American Motors) used a regular
>ingition ballast resistor in series with the pump.
>
>I seem to remember some make of car using a resistor to reduce pump noise as
>low throttle openings. Then bypassing the resistor near WOT to insure adequate
>fuel flow.
>
>I think late model Chryslers use a variable (most likely PWM ) fuel pump on
>their single line EFI systems.  They have eliminated the return line on some
>engines.
>

Ahem--well, a motor with a PM field has a rather constant level of
excitation, so it seems pretty safe to say that it would act pretty much
like a shunt wound motor--speed will vary with voltage, and torque will
vary with current. Your examples prove the point that low voltage will not
hurt them. Setting fuel pressure too high will, because it would require
enough torque (current) to cause meltdown.

Regards, Greg

>Harold