interrupt current flow to the attenuators and the thermocouple, plus a set of
diodes which provide additional protective features.
It is characteristic of
periods of time. Diodes CR701 through CR704 (fig 2-6) appear across the input of
the A54 portion of the 540B and are biased in such a manner as not to conduct under
normal operation. In the event of an overload, these diodes conduct and provide an
alternate circuit, shunting the input to the thermocouple until the protection
Protection disable circuit