Device for monitoring overcurrent of self-conducting semiconductor switch i.e. junction FET, has monitoring circuit that produces electrical signal when test voltage exceeds preset threshold value during conductive phase of switch

摘要

The device has a driver circuit for producing control signals for a control electrode of a self-conducting semiconductor switch (12). An upper driver potential (18) of a driver voltage supply (10) is connected with a source electrode (12b) of the switch. A production device produces test voltage (13) outside a supply voltage range of the driver circuit in a test line (14) that is connected with a drain electrode (12a) of the switch. A monitoring circuit produces an electrical signal when the test voltage exceeds a preset threshold value during a conductive phase of the switch. An independent claim is also included for a method for detecting an overcurrent condition in a self-conducting semiconductor switch.