Integrating analogue=to=digital converter e.g. for weighing appts.

摘要

An integrator (21) has its first input switched between the positive supply voltage (19), the negative supply voltage (18) and the measured signal voltage (30). The integrator output (27) supplies a signal alternately derived from the 3 inputs. A comparator (25) has its first input connected to the output (27) of the integrator and the second input (24) switched between the positive and negative supply voltages (19,18). The comparator output causes a timer device (31) to stop when both input signals (27,24) are equal.