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:
Sep. 13, 2005
Filed:
Nov. 16, 2002
Karlheinz Panzer, Schwebheim, DE;
Peter Hartmann, Lohr-Ruppertshütten, DE;
Karlheinz Panzer, Schwebheim, DE;
Peter Hartmann, Lohr-Ruppertshütten, DE;
Bosch Rexroth AG, Lohr/Main, DE;
Abstract
When using solenoid coils in an explosion-hazard environment, in order that no sparks are produced in the event of a discontinuity in an electrical line leading to the solenoid coil, two or more identical zener diodes are connected in parallel with one another and to the solenoid coil. In order to verify the operability of all the zener diodes which are connected in parallel with one another and to the solenoid coil, the electrical values of the zener diodes and of the solenoid coil are measured before assembly. The total capacitance of the circuit arrangement is measured after assembly. The capacitance of the solenoid coil is subtracted from the total capacitance, and the remaining value is divided by the number of parallel-connected zener diodes. The result is compared with the capacitance of a single zener diode, with the magnitude of the difference between these values being used as a criterion for the operability of the zener diodes.