Direct digital measurement of ohmic resistance - using simple programmed sequence so enabling direct reading by computer via MOS buffer amplifier

摘要

The ohmic resistance to be measured is connected in parallel with a capacitor. The digital measuring circuit produces an output signal which is fed to one terminal of a bidirectional buffer amplifier. The other terminal delivers a charge to the capacitor until the voltage across the capacitor reaches a preset level. The amplification direction is then changed and a digital counter is started. - The capacitor discharges through the resistor until the voltage across the capacitor has dropped to another predetermined level. At this point the amplifier stops the digital counter. The number stored in the counter is proportional to the ohmic value of the resistor under test. (7pp Dwg.No.0/1)