A system which uses LED pulsing, the Transmutascope, is block diagrammed at left.
In order to get the very bright flashes needed, 8 LEDs are pulsed at high currents: 3 amps per LED. The pulses are brief, and only on only a small percentage of time, therefore installing a power supply capable of supplying the full 24A peak load would be wasteful. Instead, a large power buffering capacitor is used to supply this peak load. The 1 ohm power resistor (left of cap) prevents the power supply from "dropping out" during the capacitor's recharge. It also effectively isolates the 2 circuit boards from major powerline noise caused by the LED pulsing.
The 1 watt white LEDs each have a 1 ohm resistor (not strictly necessary) to even out load sharing.
The key element of the system is the LED Pulse Controller circuit. It handles the important task of making sure the LEDs don't stay on too long. Keep in mind that unlike a typical LED circuit, there is virtually no current limiting resistance here. If the LEDs were commanded to stay on a bit too long, they would all be destroyed. The LEDs are low-side-switched on for about 800uS each time a trigger occurs. The trigger is provided by an optical slot sensor.