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:
Nov. 22, 1994
Filed:
Jul. 21, 1992
Alan W Wilkerson, Cedarburg, WI (US);
Other;
Abstract
A motor control for a treadmill has an improved, inexpensive, and simple set of power supplies, derived from the bus voltages of the DC busses with simple voltage dividers, to supply operational amplifiers connected to the positive DC voltage bus with a dual voltage supply and a common or neutral, and to provide a single voltage power supply connected to the negative bus for the driving circuitry of a motor energization switching controlling element. The dual power supply for the operational amplifiers comprises a voltage divider containing two, series connected zener diodes in series with a resistor. The one of the series connected zener diodes is connected to the positive DC voltage bus, and the resistor is connected to the negative DC voltage bus. A common connection between the two zener diodes becomes the neutral or common voltage for the operational amplifiers, and the zener diode voltages become the positive and negative supply voltages for the amplifiers. The power supply for the driving circuitry of the switch element is structured with a voltage divider comprising one zener diode and a series connected resistor. In this case, the zener diode is connected to the negative bus and the resistor to the positive bus. Isolation between the two power supplies is accomplished with optical, capacitive, or transformer isolation. The regulating circuit of the motor control may include circuitry for compensation for the inductance voltage drop in the armature circuit of the motor.