I want to construct a circuit dc12v/35w from ac 12v/35w bike alternator 120hz .
Application -install new 35w hid light.
input float voltage 7-16V ac 120hz
expected output 12v /35w
i tried with full bridge and lm2575 switching regulator . but its failure . input voltage too high so its burned.
any help
It is a 40 volt part. It should not have burned because of high voltage.
It is a 1 Amp part and you want 3A. That is a problem.
Usually this part is used as a 'buck' so the output voltage is less than the input voltage. Example 16V in will output 12V. But it needs 2 volts drop to work. So Vin of 12V will output 10V. Vin=20-->Vout=12.
More information please. Schematic and photo will help.
Sam, where is the 120Hz in the circuit??? The alternator in the bike puts out a range of frequencies and voltages depending on engine speed...
Seems to me that you need to full-wave rectify the alternator to produce DC, use a huge electrolytic filter capacitor for filtering, and then either series-regulate, or shunt regulate to make ~14V DC.
Seems to me that you need to full-wave rectify the alternator to produce DC, use a huge electrolytic filter capacitor for filtering, and then either series-regulate, or shunt regulate to make ~14V DC.
Mostly agree. but....
The generator voltage is 7 to 16V. Many types of regulators can not take 7V and make 12V. Some can.
Probably when the generator is making 7V it can not make the 35W required. Maybe 3 watts.
Mostly agree. but....
The generator voltage is 7 to 16V. Many types of regulators can not take 7V and make 12V. Some can.
Probably when the generator is making 7V it can not make the 35W required. Maybe 3 watts.
As I said before, you need a decent size 12V battery, and convert the lighting circuit to charge it.
It's NOT an easy exercise (I thought long and hard about it years ago - as the lights on my DT-400 were pretty feeble), most practical way would probably be to rewind the generator coils - and there are numerous examples of that on-line.
Mostly agree. but....
The generator voltage is 7 to 16V. Many types of regulators can not take 7V and make 12V. Some can.
Probably when the generator is making 7V it can not make the 35W required. Maybe 3 watts.
Most don't care what happens when the bike is at idle. Once the engine is turning up at speed, the alternator puts out too much; that's when the regulation is needed.
My solution would be buy a motorcycle rectifier/regulator, but then again idk if that would work, as my motorcycles stator puts out 89VAC then converts it to 14VDC through the rectifier/regulator
My solution would be buy a motorcycle rectifier/regulator, but then again idk if that would work, as my motorcycles stator puts out 89VAC then converts it to 14VDC through the rectifier/regulator
Most don't care what happens when the bike is at idle. Once the engine is turning up at speed, the alternator puts out too much; that's when the regulation is needed.
small doubt ac 12V /120hz voltage convert to dc what is the maximum output voltage in different rectifier topology(half wave,full wave, bridge rectifier)