If six solar cells are connected in series,they will
produce 3 volts at 150 milliamps (Figure 27–2). The
voltage produced by the connection is sufficient to
operate the relay, but the current capacity is not. Therefore, six more solar cells must be connected in series.
This connection is then connected parallel to the first
connection producing a circuit that has a voltage rating
of 3 volts and a current rating of 300 milliamps, which
is sufficient to operate the relay coil.