Assignment:
The SCR in Figure requires a 4-V trigger. Design a system by which the gears are shifted when a CdS photocell resistance drops below 2.5 kΩ.
![1910_system.JPG](https://secure.tutorsglobe.com/CMSImages/1910_system.JPG)
Provide complete and step by step solution for the question and show calculations and use formulas.