HOW TO WIRING PWM MODULE AND WHY?

Sometimes, I am still confusing to wire up such as LED light with dimmer functions with using PWM module. MAYBE ONLY ME. ANYWAY PWM MODULE has lots of different LOOKS from like this fancy one to small and cheap on like this

 

but it has same function and do the same job. but most different is how much current they can handle.

bigger size maybe more bigger mosfet and bigger heat sink and that make more power can through.
Please check MAX current.

SO,

If I am installing simple LED strip light about 3amp of power then, I will use 5 amp fuse and choose PWM MODULE that can handle 5amp easy.

this is diagram for  KEMO MODULE

without any mark diagram make confusing me. this is need polarity mark like this.

One of Confusing of PWM module is Why they need to connect like this.

the reason is they need consumer earth to control PWM, not positive power side .

that is why need four wire.

SO I cannot use common earth or chessie body earth for consumer.

Consumer earth is controlled like : on, off, on, off, quickly inside kemo module.

so more explain

and this little module has four wire and easy to understand how to wireup.