The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 11, 1988
Filed:
Aug. 15, 1986
Alistair A MacFarlane, East Kilbride, GB;
Marathon Electric Manufacturing Corp., Wausau, WI (US);
Abstract
A voltage regulator for a diesel engine driven alternator includes speed dip control permitting engine recovery, and a voltage signal circuit and a speed signal circuit producing a linear volts per hertz signal for controlling the RMS voltage of the alternator. A speed sensor is connected to the output of the permanent magnet generator. The signal is a filtered square wave with an accurate 50% mark-to-space ratio and converted to a pulse train coincident with the zero crossovers. A ramp circuit followed by a threshold detector and filter produces a linearly increasing voltage with decreasing speed. A level amplifier produces an output at a selected level. A rate amplifier responds to a derivative of the speed signal and clamps the level amplifier off at speed changes below a selected rate. A large and rapid speed change creates an output signal coupled to the reference side of an error amplifier to unload the alternator. The degree and rate of unloading is limited. The linear speed signal is summed with a linear RMS voltage error signal to produce a highly linear volts per hertz signal. The root mean square voltage signal is derived from the mean square of the sensed output voltage. The square root circuit is a pulse-height-width multiplier connected in a negative feedback loop to an operational amplifier to produce an implicit divider circuit. The non-inverting input is connected to the mean square signal and the amplifier forces the squared output signal equal to such mean square value, such that the output is in fact the square of the mean value.