Monostable multivibrator circuit diagram and its working. It can be used as timers, delay circuits, gated circuits etc. Read this post for more details about its circuit, operation and uses.

Use the potentiometer for setting the timing period within these intervals. For the 0.3 second to 10 minutes timer version the potentiometer is 100kΩ, R1 = 9.1kΩ, R2 = 910kΩ, R3 = 220kkΩ and C1 = ...