An important circuit to protect:

1- The power supply from short-circuit and overload that damage transformers, mosfet, transistor and other electronic components.

2- The circuit protects from overload, which causes heat components and devices and can set on any value from 200ma to 10A by potentiometer trimmer R2

3- The circuit protects from fires caused by short-circuiting devices connected to the high-current ampere battery.

4- The circuit contains a green LED that means: protection is activated.

5- The circuit yellow LED that means: Relay and devices are play.

6- The circuit red LED that means: overload or short - circuit .

7- The circuit works automatically in normal current, except for the motors that have a primary overload, so you need to press the switch for a few seconds 3s until the motor starts and the current becomes normal.

8- The circuit will turn off when the motor overload value that set by potentiometer trimmer R2

9- The circuit is powered by a 12 self-volt regulating current 200 mA, and has a variable voltage input 1.5 to 30 v 10 amps to play devices and out is from 1 to 29 v. 

10- There is a place for two types of resistance 0.1 ohm 15w :First one is cylindrical type and the second is rectangular type.

Note:

*The input of the variable voltage and 12v must be from the same power supply(The same GND) 

*Add a small heat sink for 7809 voltage regulator.