i was using a relay control board with 7805 connected. it worked fine for 6 months. now its 7805 started heating. i have changed the 7805 IC but it still heating. its changing 12 V to 5 V. can it be due to malfunction of diode attached to supply or malfunction of resistance attached?
kindly help
See if there is any short on the board or any component has shorted. Maybe the shorted component is drawing more current. Does the relays operate properly ?
thanks all for the replies. i could not come to internet so cant see post. yes there was problem with opto coupler IC attached just before 7805. it was drawing more current.