EP 1139382 A2 20011004 - Image intensifier photocathode protection circuit
Title (en)
Image intensifier photocathode protection circuit
Title (de)
Schutzschaltung für die Photokathode eines Bildverstärkers
Title (fr)
Circuit de protection pour la photocathode d'un intensificateur d'image
Publication
Application
Priority
US 53876500 A 20000330
Abstract (en)
A protection circuit for protecting a photocathode of an image intensifier tube from being overdriven during operation includes a high voltage power supply for supplying the photocathode with a photocathode potential, a measurement circuit for measuring the current supplied to the photocathode, and a logic circuit for interrupting the photocathode potential supplied to the photocathode when the measured current indicates that the photocathode is being overdriven. More specifically, the measurement circuit includes a resistance connected between the high voltage power supply and the photocathode of the intensifier tube; and a sensing circuit for sensing a voltage across the resistance. In another feature, the measurement circuit and the logic circuit are configured to float with respect to ground. <IMAGE>
IPC 1-7
IPC 8 full level
H01J 31/50 (2006.01); H01J 29/96 (2006.01)
CPC (source: EP)
H01J 29/96 (2013.01); H01J 2229/962 (2013.01)
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
EP 1139382 A2 20011004; EP 1139382 A3 20030514; JP 2001319604 A 20011116
DOCDB simple family (application)
EP 01201005 A 20010319; JP 2001074214 A 20010315