APPLICATIONS_______________________________________________________________________________________
ELECTRONICS DESIGN LAB
Charging information is sometimes printed on the batteries.
The technician or engineer working in an engineering
Battery charging, at least initially, requires the constant
laboratory requires a dc power supply to power breadboard and
current mode of operation. Before connecting the power
prototype circuits. This power supply is ideal because it
supply to the battery, preset the VOLTAGE controls to the
monitors output current and voltage, limits current to protect
fully charged terminal voltage specified by the battery
the circuit, is adjustable over a wide range, and has excellent
manufacturer. Turn off the power supply while connecting
regulation and very low ripple.
the battery. Observe proper polarity and connect as for
Use of the instrument in an engineering laboratory is very
constant current operation. Adjust the CURRENT control
similar to that described for servicing electronics equipment
for the maximum charging current specified by the battery
and modules, except that lower currents may be prevalent when
manufacturer (If the maximum charging current is greater
powering individual circuits. The current limiting feature is
than the power supply’s maximum load current, set the
very valuable in this application because it can protect
CURRENT control to maximum). The CONSTANT
unproven circuits from damage.
CURRENT indicator will light and the battery will charge at
the preset current limit. As the battery approaches full
ELECTRONICS EDUCATION
charge, its terminal voltage will approach that of the power
The student in an electronics curriculum may use the power
supply output and the charging current will taper off. The
supply for powering equipment and circuits as previously
power supply may automatically switch to constant voltage
described for all other applications. In addition, the power
operation. When this occurs, the power supply will continue
supply can be used in the classroom laboratory to conduct
to provide a trickle charge.
experiments in fundamental electronics. In learning Ohm’s law,
for example, the relationships of resistance, current, and voltage
SPLIT SUPPLY
are easily demonstrated by the use of a power supply.
Frequently, “split power supplies” are required for
amplifiers and other electronic circuits. The Model 1651A is
BATTERY CHARGING
ideally suited for “split power supply” operation. This supply
The power supply can be used as a battery charger to restore
can be configured to provide two positive voltages with a
the charge in rechargeable batteries such as lead-acid, nickel-
common negative, two negative voltages with a common
cadmium, and some alkaline types. Refer to the battery
positive, or one positive and one negative with a common
manufacturer’s charging specifications for proper voltage and
ground. In addition, each of these configurations can be
current settings.
obtained with identical or differing voltages.
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