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. 15, 1994
Filed:
Jun. 14, 1993
Gary R Cadman, Norwell, MA (US);
Scully Signal Company, Wilmington, MA (US);
Abstract
A dynamically self-calibrating, intrinsically safe DC--DC power supply generates a controlled output voltage during normal operation and limits the output voltage and current during fault conditions, such as applied overvoltages or short circuits within the supply. The supply has a voltage regulator for generating a controlled output voltage in response to a feedback voltage applied to a control terminal. The supply also has a voltage-clamping Zener barrier, which includes (i) a power Zener diode connected between the output and control terminals of the regulator for supplying the feedback voltage thereto, which is reverse-biased during normal operation of the supply, and (ii) a non-linear, low impedance path between the control terminal and ground in parallel with a resistor. The feedback voltage causes substantially constant current to flow through the diode during normal operation, thereby dynamically compensating for any variation in breakdown voltage of that Zener diode. By operating normally with minimal current through the diode, the supply's output power can be optimized without compromising the intrinsically safe operation of the supply.