Application of the transition process in the RC circuit

Current pulse generator


R1 << R
because R1 is small, then I ↑, EMF is not large. Capacitor C charged to EMF E.


Before the key is closed, the capacitor charges to Uc = E, since R >> R1
After closing the key at the first moment R1 a little current is very large. The surge current I is called a pulse.
It is used, for example, when translating the arrows of trams and electric trains.