Through this submit we shall analyze a basic high current mosfet based solid state relay, that are available in place standard bulky mechanical relays.
A clear-cut high current solid state relay or an SSR may be designed implementing a handful of mosfets and an optocoupler, as established in the digaram above.
The concept appears easy to follow.
In an lack of an external trigger, the lower mosfet remains turned OFF permitting the upper mosfet to perform by means of the 10k resistor linked across the positive and the gate of the mosfet.
This permits the N/C contact to get effective, and a DC load linked across the supply positive and the N/C gets started in this particular circumstance and vice versa.
On the other hand in the existence of an input trigger, the mosfet associated with the opto emitter receives a chance to activate, switching OFF the upper mosfet.
In this circumstance a load hooked between positive and N/O points gets initiated or vice versa