How to make a short circuit alarm for power supply?

[ex4]

Anybody can give me an example on how to make a short circuit alarm for power supply?? I want the output is a 5-12V buzzer, so it will get the attention of the user immediately when a short circuit occurs

 

[fenugrec]

Re: Short Circuit Alarm

Is there a fuse in it?
When you short the output, the fuse blows and whatever you're powering
turns off. Why do you need a buzzer as well?

 

[ex4]

Re: Short Circuit Alarm

Is there a fuse in it?

-> yes, there is a 5A fuse but my PSU is limited to 1,6A max out, so it will not get blow up. I use L200 regulator.

Why do you need a buzzer as well?

-> a howling sound from buzzer will draw attention of the user ASAP right

 

[yousafzai]

Re: Short Circuit Alarm

Use an inline insertion resistor having a value of 0.01 ohm and measure the voltage drop across it. Then amplifiy this into current and using a comparator activate a transistor to sound an alarm, if a preset value is exceeded.

 

[fenugrec]

Re: Short Circuit Alarm

Sure, a buzzer will get his attention... on my power supply though
I hear the fan RPM going down if I overload one output, and i usually
see the circuit losing power.

But consider this: if you short your power supply, do you still have
power to drive your buzzer? Do you have another external power
source ? If you only have a shorted power supply, you won't be able
to drive your buzzer...

 

[ex4]

Re: Short Circuit Alarm

But consider this: if you short your power supply, do you still have
power to drive your buzzer? Do you have another external power
source ? If you only have a shorted power supply, you won't be able
to drive your buzzer...

that's the beauty of L200, it won't cut off the input voltage

Use an inline insertion resistor having a value of 0.01 ohm and measure the voltage drop across it. Then amplifiy this into current and using a comparator activate a transistor to sound an alarm, if a preset value is exceeded.

any schematic example???