I need to Polarity Protect a 24v Dc to 12v Dc converter, the unit is rated to 3Amps. Having read the various different threads on this topic i was looking to go with a bridge rectifier to switch the polarity automatically. Any ideas on a suitable model Schottky Barrier Rectifier that will be suitable for this use.
Also would it be wise to install a fuse in this circuit to protect from overload as the supply is upward of 3Amps? Would
the fuse need to be fitted after the bridge rectifier on the posotive side or can it be positioned before it with the unknown polarity?
I have worked on avionics and ham gear which typically has a series fast-blow fuse, and a shunt normally reversed-biased Silicon diode. That way, there is only a tiny forward drop across the fuse. The diode conducts only if the input polarity is reversed, and the fuse vaporizes...
Putting one or two diodes in the forward path would create an unacceptable voltage drop on most of the gear I am familiar with...
A bridge rectifier sounds like it should work for you, assuming the converter can tolerate the voltage drop of the bridge. I'm wondering why you want to use Schottky?
A bridge rectifier sounds like it should work for you, assuming the converter can tolerate the voltage drop of the bridge. I'm wondering why you want to use Schottky?
What sort of circuit is your converter? Is it a linear regulator, or a switcher? Most converters with 12V output can tolerate 22V input as well as 24V.
What sort of circuit is your converter? Is it a linear regulator, or a switcher? Most converters with 12V output can tolerate 22V input as well as 24V.
I don't know where you are, but a bridge like this should work. You might find something cheaper or more suitable. A Schottky bridge might save a little power if your converter is switch mode.