MEASUREMENT SYSTEM FOR INPUT BIAS –OFFSET CURRENTS OF AN OPERATIONAL AMPLIFIER
A very simple microprocessor (µP) -based dedicated instrument is designed here.' The Overall system design consists of both hardware and software designs. This set-up yields the exact values of input bias and input off-set currents on the µP display panel, one after the other, when the operational amplifier (OP- AMP) under test is connected across the test terminals.
Microprocessor Based Instrument for Resistance and Diode Testing
The component tester reported in this paper is a microprocessor based instrument. It is used for evaluating resistances in the range of 100–10M Ohms divided equally over five automatically selected ranges. It has also got the capability of testing silicon diodes for their usefulness. The diode can be connected in any particular fashion. The hardware circuit is IC based and includes resistance detector, relay drivers, buffer, constant current source, diode tester, analog to digital converter and Intel 8085 based programmable microprocessor kit.
A microprocessor-based switched-battery capacitance meter
A microprocessor-based, switched-battery capacitance meter has been developed. It consists of an analog part, based on a previously designed capacitance meter, and a digital part in which a microprocessor and a timer perform the main functions. The capacitance is measured indirectly by means of a time constant measurement. Two phases of the measurement process are involved in measuring the capacitance. The first phase, when a capacitor is charged, is based on the software counter-timer measurements. The second phase, when the capacitor is discharged, requires a hardware timer controlled by the microprocessor. The digital hardware reflects a different approach than used for the previous construction. >