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Solid States Devices => solid state devices => Topic started by: magnetman12003 on July 07, 2015, 09:36:01 PM

Title: Voltage step down from solid state full wave rectifier
Post by: magnetman12003 on July 07, 2015, 09:36:01 PM
My full wave bridge rectifier has an output of 140 volts DC.
How do I decrease the output to 12 volts DC without using a power robbing resistor in
series with the rectifier?


I would like to have as much current as possible-- is there some type of module that can do this job or a simple circuit?


All help greatly appreciated.  If possible hand draw whatever circuit or tell where I can find a module.
Title: Re: Voltage step down from solid state full wave rectifier
Post by: MarkE on July 07, 2015, 11:00:01 PM
Quote from: magnetman12003 on July 07, 2015, 09:36:01 PM
My full wave bridge rectifier has an output of 140 volts DC.
How do I decrease the output to 12 volts DC without using a power robbing resistor in
series with the rectifier?


I would like to have as much current as possible-- is there some type of module that can do this job or a simple circuit?


All help greatly appreciated.  If possible hand draw whatever circuit or tell where I can find a module.
For power up to about 10W buy and connect a 12V wall wart.  For higher powers buy a 120VAC to 12V power supply.  You will have to check to make sure the supply you buy does not use a voltage doubler style front-end which is unfortunately very common as it allows one design to handle 110/120VAC and 220/240VAC sources.  Supplies that use a doubler have a voltage selection switch.  Supplies that do not use doublers are labeled "universal" and do not have an input voltage selector switch.
Title: Re: Voltage step down from solid state full wave rectifier
Post by: TinselKoala on July 08, 2015, 12:00:27 AM
Put a step-down transformer on the AC side of the FWB.