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:
Apr. 27, 1976
Filed:
Feb. 12, 1973
Fount E McKee, Houston, TX (US);
Delta-X Corporation, Houston, TX (US);
Abstract
A control circuit for turning off the power to the pump drive motor when the pump has exhausted the supply of liquid in the well. Means for sensing the instantaneous current to the pump motor and a circuit measuring the average current drawn by the pump drive motor, and turning off the power when the average current decreases below a preset level. An RC circuit having a time constant greater than the time required for the pump to complete one full pumping cycle for measuring the average current to the motor, and a comparator controlling switching means to shut off the power when the average current to the motor decreases to a predetermined amount. A reference voltage supplied to the comparator from an amplifier connected to the electrical power in which the output of the amplifier varies inversely to variations of the voltage of the electrical power thereby preventing fluctuations in the supply voltage from adversely affecting the control circuit.