Pulstrømmen

Pulstrømmen, or the pulsed current, is a term used in electrical engineering to describe a current waveform that is non-continuous and consists of short, high-intensity pulses rather than a steady flow. The concept is central to pulsed power and high-speed electronics, where energy is delivered in brief bursts to a load or system. The spectral content of pulstrømmen is broad, including significant harmonic components due to fast rise and fall times.

Key parameters include peak current I_peak, pulse width t_p, rise time t_r, and fall time t_f, repetition rate f (or period T), and duty cycle D = t_p/T. The waveform shape may be rectangular, exponential, Gaussian, or more complex. The energy delivered per pulse depends on the load and circuit; for a resistive load, E_p ≈ ∫ i^2 R dt, while for a capacitive or inductive load, energy transfer depends on the instantaneous voltage and impedance.

Pulstrømmen is produced by switching devices and pulse-forming networks. Methods include capacitor banks released through fast switches, Blumlein or other PFN transmission lines, and Marx generators. The choice of topology affects rise/fall times, jitter, pulse repetition rate, and impedance matching to the load.

Applications span radar and communication systems, pulsed laser pumping, medical defibrillators and other cardio-impulse devices, materials processing, and scientific research such as particle accelerators. In research environments, pulsed currents enable high instantaneous powers while keeping average power within safe limits.

Measurement and safety: measurement of pulstrømmen uses current probes, shunts, or Rogowski coils, often rated for high di/dt. Careful design addresses impedance, reflections, and electromagnetic interference, as well as safety hazards from high voltages and stored energy in pulse-forming networks.