APPLICATION
ELECTRONICS DESIGN LAB
The technician or engineer working in an engineering laboratory requires a dc power supply to power breadboard and prototype circuits. This power supply is ideal because it monitors output current, output voltage, limits current to protect the circuit, is adjustable over a wide range, and has excellent regulation and very low ripple.
Use of the instrument in an engineering laboratory is very similar to that described for servicing electronics equipment and modules, except that lower currents may be prevalent when powering individual circuits. The current limiting feature is very valuable in this application because it can protect unproven circuits from damage.
ELECTRONICS EDUCATION
The student in an electronics curriculum may use the power supply for powering equipment and circuits as previously described for all other applications. In addition, the power supply can be used in the classroom laboratory to conduct experiments in fundamental electronics. In learning Ohm’s law, for example, the relationships of resistance, current, and voltage are easily demonstrated by the use of a power supply.
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BATTERY CHARGING
The power supply can be used as a battery charger to restore the charge in rechargeable batteries such as lead- acid, nickel- cadmium, and some alkaline types. Refer to the battery manufacturer’s charging specifica tions for proper voltage and current settings. Charging information is sometimes printed on the batteries. Battery charging, at least initially, requires the constant current mode of operation. Before connecting the power supply to the battery, preset the VOLTAGE controls to the fully charged terminal voltage specified by the battery manufacturer. Turn off the power supply while connecting the battery. Observe proper polarity and connect as for constant current operation. Adjust the CURRENT control for the maximum charging current specified by the battery manufacturer. (If the maximum charging current is greater than the power supply’s maximum load current, set the CURRENT control to maximum). The
CCindicator will light and the battery will charge at the preset current limit. As the battery approaches full charge, its terminal voltage will approach that of the power supply output and the charging current will taper off. The power supply may automatically switch to CV (constant voltage) operation. When this occurs, the power supply will continue to provide a trickle charge.
