Left panel: a cartoon image representing the four high-voltage supplies that select electrons in SPAN-E as a function of time (arbitrary) for a full energy and deflector range sweep. From top to bottom: the hemisphere (select for energy), deflectors 1 and 2 (select for theta direction), and spoiler (attenuate by energy). The signals in the above plot have been normalized and skewed by a constant value relative to one another; hence, no axis labels are provided. The vertical dashed lines represent changes in the hemisphere value, during which time the deflectors will scan through θ in discrete commanded steps as stored in the instrument tables. The spoiler changes value at the same time as the hemisphere; thus, electrons of a specific energy are attenuated with a constant factor of attenuation in all look directions below 500 eV. Right panel: a typical full sweep pattern showing voltages from the four swept HV supplies in SPAN-E. The signals are offset and normalized to their maximum values to show their relative timing. Note that the hemisphere supply sweeps from a high value to a low one: in other words, SPAN-E scans high energies in an individual sweep before low energies. The spoiler supply is held constant at high energies and steps down in voltage synchronously with the hemisphere at lower hemisphere voltages. The deflector supplies alternate, which is biased and which is held at ground.