Originally shared on the public FactorioPrints / Factorio School archive (factorioprints.com · factorio.school). Authorship preserved from the public catalog.
Velocity Controlled Pulse Frequency Modulator for fuel pump
attach green wire from constant combinator to main hub (read velocity and planet info)
outputs fuel symbol to light (can bypass and delete) then to pumps (enabled if fuel symbol > 0)
set desired velocity in constant combinator with a negative in front