Operating instructions

Introduction To Programming
24
Common Commands
Common commands, while not part of the command tree, can be mixed in with regular commands. The electronic load
responds to the Common commands and queries listed in Figure 4-1 of the Language Dictionary. You can mix Common
commands in with regular programming statements; the Common command will be executed without affecting the position
of the parser.
Programming Examples
The following programming examples are practical applications of the electronic load. Although they are in HP Series 300
Basic, the principles can be applied to any other version of BASIC or even to another language.
Battery Testing
The principal measurement of a battery’s performance is its rated capacity. The capacity of a fully charged battery, at a fixed
temperature, is defined as the product of the rated discharge current in amperes and the discharge time in hours, to a
specified minimum termination voltage in volts (see Figure 3-5). A battery is considered completely discharged when it
reaches the specified minimum voltage called the "end of discharge voltage" (EODV).
Figure 3-5. Typical Discharge Curve
In this example, the electronic load discharges three nickel-cadmium batteries to determine their discharge rates at a fixed
temperature (see Figure 3-6). The batteries are connected in series so that when the EODV is reached, it is still above the
minimum operating voltage of the electronic load. The EODV for nickel-cadmium batteries is typically 1.0 volts.
Power Supply Testing
A typical use for electronic loads when testing power supplies involves power supply burn-in. One of the problems
associated with burn-in is what to do if the power supply fails before the test is over. One solution involves continuously
monitoring the supply and removing the load if the supply fails during the test (see Figure 3-7).