Amid rising energy supply risks in the late 1960s, Joel Spira, founder of lighting company Lutron, recognized an opportunity to increase the efficiency of fluorescent lighting. He sketched this idea for an energy-efficient fluorescent light dimmer, based on a modulating circuit that would increase the frequency of the electrical current (illustrated with cross-hatches in the frequency wave). This higher frequency generated more light per watt of power, which became a salient advantage when energy prices increased.