I am tryin to find out how i can protect my LCD monitors in the car from an overvoltage . max voltage is 12V and im sure its 13.5 or so when charging.
will a rectifier work ??? or a regulator of some type?? :blink:

 

hi,

usually the LM7812 will do the trick, but if you very particular that the voltge does not exceed 12v, this regulator has an output tolerance of +/-5%. so chances are it would still exceed the 12v, but i don't think the 0.6v extra would affect your gadget.

 

Originally posted by mozikluv@Dec 1 2004, 10:25 AM
hi,

usually the LM7812 will do the trick, but if you very particular that the voltge does not exceed 12v, this regulator has an output tolerance of +/-5%. so chances are it would still exceed the 12v, but i don't think the 0.6v extra would affect your gadget.

[post=3879]Quoted post[/post]​

The 7812 regulator is not very good for this.
For it to give you 12V you need another 3V.
You should rather use low dropout regulator LT1086-12 (V0ut=Vin+0.5) or switchng regulator such as LMLM2575-12.

 

The 7812 regulator is not very good for this.
For it to give you 12V you need another 3V.
You should rather use low dropout regulator LT1086-12 (Vin=Vout+0.5) or switchng regulator such as LM2575-12.

 

thanks for your time guys ......... im gonnnnna research it and see where i can find them

 

P.S. you guys are really smart ! thx again

 

Originally posted by mozikluv@Nov 30 2004, 09:25 PM
hi,

usually the LM7812 will do the trick, but if you very particular that the voltge does not exceed 12v, this regulator has an output tolerance of +/-5%. so chances are it would still exceed the 12v, but i don't think the 0.6v extra would affect your gadget.

[post=3879]Quoted post[/post]​

you can use a32-tnt relay oto protect from over voltage more than 0.12 volts