I have an electrical transformer with 4 wires.. an orange pair and a black pair.. I have measured the resistance across the black pair, and it is significantly higher than the resistance in the orange pair.. I plan to connect this transformer to my mains and see if it steps down the voltage.. also I plan to build a rectifier circuit to convert my voltage into DC.. I am however a bit scared of connecting the transformer to the mains because this is 220/240 volts and might be harmful to me... just seeking an experts opinion please.. thanks for reading
Do not connect just any old transformer that you may have laying around up to the AC Mains.
Make sure that the transformer is rated for mains operation. If the unit you have is unlabeled or has no identifying numbers and corresponding data sheet then set it aside.
Safety and protection of your self and the property around you is the primary consideration here. It is far better to obtain correct components than it is to quibble over the cost savings of some piece of surplus junk that you know nothing about.