Maydori Posted November 1, 2016 Posted November 1, 2016 Hello, I've a circuit shown like this image, that used to measure the current through shunt resistance , The circuit have analog & digital ground , the terminals 1 ,2 ,3 are for AC source . I need to protect this circuit from shorts . I actually try it out & booom kaboom happened !!! I lost an expensive chip !!! , this circuit operates UC, ft232rl ftdi , ADE7355 , lot of chips . So where's the right place to put the fuse ? & how to know that this is the right place ? Will be a fuse on the digital side and the analog side ? any other recommendation for this circuit ? I found out that 7805 voltage regulator is getting hot fast . R3 is shunt resistor with 200 u ohm resistance
BravoYankee4 Posted November 1, 2016 Posted November 1, 2016 Hello, I've a circuit shown like this image, that used to measure the current through shunt resistance , The circuit have analog & digital ground , the terminals 1 ,2 ,3 are for AC source . I need to protect this circuit from shorts . I actually try it out & booom kaboom happened !!! I lost an expensive chip !!! , this circuit operates UC, ft232rl ftdi , ADE7355 , lot of chips . So where's the right place to put the fuse ? & how to know that this is the right place ? Will be a fuse on the digital side and the analog side ? any other recommendation for this circuit ? I found out that 7805 voltage regulator is getting hot fast . R3 is shunt resistor with 200 u ohm resistance In general fuses should be placed first in a circuit (close to the power supply), else it will not really protect the circuit. What kind of AC voltages do you have in this circuit? What is the purpose of the 5VDC and why are you feeding the regulator with AC? A 7805 generates a lot of heat, so always try to have the input voltage as close to the output voltage as possible.
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