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. 15, 1991
Filed:
Jun. 23, 1989
Martin E Willcocks, Los Angeles, CA (US);
Rhett McNair, Lake City, FL (US);
Other;
Abstract
An improved lamp switching circuit for switching on a second lamp circuit upon every alternate application of power to a first lamp circuit. A magnetic latching relay alternately connects and disconnects the second lamp circuit in parallel with the first whenever power to the circuit is switched off. The relay is powered by the discharge of one of two capacitors, which respectively operate a set circuit and a reset circuit of the latching relay. Only one of the capacitors is charged at any time. While power is applied to the lamp circuits, one capacitor is charged while the other is kept discharged, in preparation for operation of the latching relay. When power is switched off, a control circuit senses this condition and triggers a thyristor to discharge the capacitor through the corresponding relay coil after a short predetermined time delay. A low voltage regulated power supply is derived from the a.c. power to provide the power needed by the control circuit and to charge the capacitors, making the circuit operation reliable over a wide range of supply voltages and temperatures.