Multifunction Programmable Current/Voltage Source
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
This article describes a circuit arrangement which provides a constant current or voltage with magnitudes defined under program control. In order to diagnose electrical problems in the automobile utilizing a technician terminal, it is a requirement to have a probe card which has the capability of sourcing voltages and currents under the control of the terminal. It is the requirement of the circuit arrangement disclosed herein to provide the 1) +12 volts or +5 volts with current limited to 1 ampere, 2) constant current sourced under program control of up to 100 mA. Figs. 1 and 2 show the present circuit. Fig. 1 embodies a voltage source whose output is 0 volts (turned off), +12 volts, or +5 volts depending on the logic states of the control lines "volts on" and "switch +5/BAT". "Volts on" turns the output on or off.