Abstract: A motor driven mechanical positioner is provided which will position a movable arm to any one of 840 discrete angular positions. A total angular range of +/-42.degree. can be covered in 0.1.degree. increments. Electronic circuitry controls the nonlinear drive mechanism. A drive shaft wheel has six evenly spaced holes through which light from an IR LED is allowed to shine on a phototransistor placed on the other side of the wheel. As a result of the intermittent light striking the phototransistor, six clock pulses are generated for every revolution of the drive shaft. A desired angular position is entered into the electronics via thumb wheel BCD switches. The BCD information from the switches is transformed into binary information to address EPROMs. For each possible binary address representative of a desired angular position, the selected EPROMs output binary data that is representative of the clock pulse count for that particular angular position.

Abstract: An audible test device which provides a tone when a resistance being measured is less than a selected value, the selected value being variable to a few milli-ohms. A first or second source of voltage is applied to a constant current source. The constant current generated is divided between two paths, one path including test leads holding the resistance being measured therebetween, the other path through a voltage adjusting device. The output from the voltage adjusting device is applied to one input of a voltage comparator, the voltage appearing across the resistance under test being applied to the other input of the voltage comparator. The output of the comparator is applied to a voltage controlled oscillator (VCO), the output of the VCO being applied to a piezoelectric device and to a speaker operable only when the second voltage source is utilized, thereby generating an audible tone.