English: Animated diagram showing the operation of a Blumlein transmission line pulse generator, an electrical circuit which produces very short current pulses, used in pulsed power devices such as lasers, particle accelerators, and high voltage insulation testers. The advantage of the Blumlein circuit is that its output voltage is equal to the power supply voltage V, while a simple charged transmission line generator (shown in companion file File:Charge line animation.gif) has an output of V/2. The Blumlein consists of two transmission lines in series with the load Z_L between them. The lines are charged by a high voltage DC power supply attached to one end (left). A switch short-circuits the line at the power supply end, creating a voltage step which travels toward the load. Since the load Z_L is twice the characteristic impedance of the line Z₀ the step is half reflected and half transmitted, creating two symmetrical opposite polarity voltage steps which propagate away from the load, leaving between them a voltage drop across the load of V/2 - (-V/2) = V. The voltage steps reflect from the ends of the line and return, ending the voltage pulse across the load. The duration of the output pulse is 2D/c, where D is the length of each transmission line and c is the velocity of the pulse on the transmission line.