How to use the microcontroller switch to control the length of the circuit section time
The simplest solution: single-chip + relay + transistor drive, or not enough current to drive the relay
SCM to be programmed, compiled after the burn into the implementation of single-chip, not two or three words can understand. If you control the circuit off time is fixed, you can buy a "refrigerator companion" to use, very cheap.
Use the timer inside the microcontroller to determine the time; use the microcontroller IO control port, to control the circuit off. Look at your question is the need for a clock chip DS1302 DS12C887 or PCF8563 like the RTC. MCU from the clock chip to read the current time, and you have to control the time contrast, you need to control the time, turn off or open the control circuit
