[SOLVED] 7805 gets heated up........

[Deexith Hasan]

in my PIC18F development board 7805 gets heated up fastly and gives 0.70 volt o/p.......7805 is connected with heat sink and decoupling and coupling capacitors......input is 12 volt...


checked continuity bet ween o/p and GND and heared beep sound in multimeter.....so is there any short circuit in my development board,so 7805 is getting heated up or there is a problem with 7805?

 

[milan.rajik]

Yes, if the o/p of 7805 is shorted with GND then you here the beep. Maybe it is a poor quality development board.

 

[betwixt]

It sounds like a short or something drawing excesive current is pulling the 5V down. Basically the regulator cannot provide enough current to maintain 5V output so the voltage has dropped and the regulator is heating because of the extra power it is being asked to dissipate.

Brian.

 

[spudboy488]

The 0.7V output may lead to a shorted/reversed transistor or diode. That may be a clue to where to look for the issue.

 

[milan.rajik]

I think 7805 itself is shorted.

 

[hobbyckts]

Remove the decoupling capacitors first check for continuity. If problem still persists then remove and check the 7805 IC