Voltage controller?

[Clarence L.Snyder]

U> se a voltage to grequency conversion, then have the frequency output
> drive a 555 oneshot. By tuning both the frequency output and the pulse
> width you pwm control the pump.
> I'm no engineer either, but both circuits are bretty simple. Could
> likely use 555 for both stages, or even run one as a monostable with the
> MAP connected to the control terminal - would give you roughly 2:1 ratio
> range?
> 
Just thought of a possibly simpler method. Use a FORD MAP, which is a
variable frequency output, and run the one-shot off of it.