Found in American documentation from the 90's, this JFET stage has an input impedance of 500 M ohms. Bipolar transistors are general purpose types and the FET supports an equivalent.
This circuit was found in an old European documentation. When R2 is cut off the circuit triggers...
August 2017 - Bourns Multifuse AEC-Q200 PTC resettable fuses can be obtained from Mouser...
September 2016 - Mouser Electronics is providing new ultraviolet LEDs VLMU1610 of Vishay suitable...