# How can I create an RL circuit?

I want to create a RL circuit that has a dc voltage source, lamp, switch, R and L elements are connected in series. How can I design the circuit so that the lamp flashes from the moment the switch is turned off?

The lamp has no value, just to understand the energy use.

• You have specified how you want everything wired and then asked us how to design it. Edit required. – Transistor Jan 22 at 23:56

You can estimate the pulse duration time constant from $$\tau = RL$$.