Apart from the DA163 quad amplifier module, the IN163 dual
integrator module is the most complex module of the whole
Hitachi 240 analog computer. It contains the necessary
electronics for two high precision integrators, each of which
requires an operational amplifier from a DA163 module to
work in a computing setup.
The idea of analog integration in electronic analog computers
is to use a (precision) capacitor in the feedback loop of a
very high gain operational amplifier. For practical applications
this feedback capacitor should be selectable for its capacity
to allow different time scales for integration.
Apart from this there has to be a way to charge the capacitor
to a given value prior to a calculation to implement initial
conditions.
