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:
Jan. 03, 1978
Filed:
Apr. 23, 1975
Lindsey E Waldorf, Ann Arbor, MI (US);
Kenneth E Monroe, Ann Arbor, MI (US);
Other;
Abstract
A control system for powering the direct current drive motor of an electric vehicle from a storage battery employs a semi-conductor switch to connect the battery to the motor. Speed control of the vehicle is achieved through operator control of an accelerator which provides an analog output voltage. A multi-vibrator provides a bi-valued output signal varying between 100% on time and 100% off time as a function of the accelerator output. The motor energizing switch is conditioned by this output and by the output of a circuit which compares the motor armature current to a reference value. The circuit includes protection elements so that the switch is opened when the armature current exceeds a preset maximum and is allowed to close again if the multivibrator is still in an 'on' mode when the armature current decays below a lower preset value.