using the junior computer as a voltmeter

using the Junior Computer as a voltmeter elektor october 1981 — 10-11 Voltmeters are always useful as far as anybody interested in electronics is con- cerned. Junior Computer owners can use this straightforward circuit and pro- gram to convert their computer into an excellent digital voltmeter. The basis of the circuit is an A/D con- verter from Intersil. This IC has binary outputs and will convert the input signal plete voltmeter circuit for a 33/4 digit display including automatic polarity indication. This means the whole circuit can be very straightforward. Figure 1 shows the circuit diagram. The voltmeter IC contains a 12 bit A/D con- verter with tri-state outputs. The out- puts B1 ... B8 are displayed in two bytes. Which byte is displayed depends using the Junior Computer as a voltmeter With the addition of a small circuit and the aid of the accompanying program the Junior Computer can be used as a digital voltmeter ... and a good one at that! The voltmeter has 3% digits an...