the test plane, a solar cell and calibrated photo-detector
(13DAS003) are placed.
A pulse power supply for an array is constructed from a high
voltage DC supply (Xantrex XDC20-600) and a pulsing circuit.
Amplitudes of pulse signals can be continuously varied from 0 to
150 V with a pulse width of 10 ms and a period of 1 s. Study is made
on power from pulsed operation (at different amplitudes, pulse
widths and pulse periods) and compared with continuous operation
of LEDs. This is to obtain the maximum power that LEDs can
withstand before being damaged due to temperature rise. For pulse
operation, we find that 2e3 times of LED rated voltages and 8e10
times of rated currents are feasible with forced air-cooling.