How can I protect a circuit?

[Dixix]

How can I protect a circuit?
If I have so much trouble with building a homemade MD, I should somehow protect the circuit from short circuit. (In the rail of power supply)
Is a simple fuse enough?
Or do I have to build a little protection circuit?
Thanks for the advice,
regards
Dixix

[kt315]

Schottky diode in power line... the fuse and a diode after it, back inverted connected to + and - power lines... cathode on +, anode on -... if you use Step Up converter it is the protection itself. if converter would be burn the circuit will be live.

[Dave J.]

Many voltage regulators, both switching and linear type, are self-protected against short circuits.

This does not necessarily protect the entire load circuit (for instance if the regulator is rated for 1 watt load but a component in the load is rated for 1/10 watt), but it's a start.

--Dave J.

[Waikiki_Sweep]

Fuse is a must! MOSFET has melted once on my Surf PI board when I detected in water. When I opened waterproof case that was a smell Also square hole has been burned through PCB and I can see fiberglass cloth inside. Hopefully after replacement of MOSFET and adding a fuse to the circuit all works OK. So be prepared, add fuse before everything go to smock not after.

[Davor]

Check the ICP-N20 device. It is a fuse, but a permanent one

[Monolith]

Here is a good explanation how to protect a circuit: http://www.onsemi.com/pub_link/Collateral/TND335-D.PDF

[Dixix]

Thanks for all the good informations!
I think a circuit protection is a very important thing. As I said, I spend a lot of time and effort to build circuits --- a small mistake by the circuit may break.
And if you can prevent that ....

If I have understood correctly, this is the quick solution here?



The ICP-N20 is a very interesting solution. The component is not easy to obtain. The best of the Chinese. Because it is cheap but the delivery takes a long time ....

[Waikiki_Sweep]

Diode will eat some voltage so it is better to put it inverted in parallel to battery.



Then if you connect battery with wrong polarity diode will conduct current and fuse will burn to protect your circuit.

[Dixix]

Diode will eat some voltage so it is better to put it inverted in parallel to battery.

[ATTACH]26970[/ATTACH]

Then if you connect battery with wrong polarity diode will conduct current and fuse will burn to protect your circuit.

Thanks.
I will first times to do it that way.
Dixix

[chemelec]

The Best Solution When Bench Testing is a Current Limited Power Supply.
Example in the case of the Surf Pi, Set current for about 100 mA.

If Excessive Current is Tried to be Drawn, the Voltage will drop.
At least this protects from Major Damage.

The Fuse/Diode is ONLY good in Preventing a Reversed Battery situation.

[Waikiki_Sweep]

Fuse can be found in every piece of electronic equipment for last ### years. It is not a shame to use one if you have a risk to get few Amperes current when some of transistors blow. Or keep fire extinguisher in good visible place