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Check out the data sheet Mark, you can add a diode or three in the commonhi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
how can i do this ?
thanks,
mark k
**Use an LM317.hi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
how can i do this ?
Download the datasheet for the 7812 from National Semiconductor, there's anhi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
how can i do this ?
"mark krawczuk" <krawczuk@adam.com.au> wrote in message
news:fbSdnXAo84XsM4bUnZ2dnUVZ_oTinZ2d@adnap.net.au...
hi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
how can i do this ?
**Use an LM317.
--
Trevor Wilson
www.rageaudio.com.au
On 2008-11-13, mark krawczuk <krawczuk@adam.com.au> wrote:
hi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
how can i do this ?
Download the datasheet for the 7812 from National Semiconductor, there's
an
example on the first page.
**Use the correct part for the job required. An LM317 costs less than ahi, this is unbeleviable, i have a specific question relating to specific
parts , and someone says use XXXX instead , next time they got a question
relating to a SPECIFIC part , i think i might tell them to use something
differant...
Might be an idea to feed the diode(s) with some bias current via a resistor"mark krawczuk" <krawczuk@adam.com.au> wrote in message
news:fbSdnXAo84XsM4bUnZ2dnUVZ_oTinZ2d@adnap.net.au...
hi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
how can i do this ?
thanks,
mark k
Check out the data sheet Mark, you can add a diode or three in the common
leg to ground to "jackup" the regulator. Diode cathode points to ground,
Each diode will add ~0.6V. Try it & see.
hi, this is unbeleviable, i have a specific question relating to
specific parts , and someone says use XXXX instead , next time they
got a question relating to a SPECIFIC part , i think i might tell
them to use something differant...
bullshite"mark krawczuk" <krawczuk@adam.com.au> wrote in message
news:OsKdnWLfhfYoBIHUnZ2dnUVZ_vKdnZ2d@adnap.net.au...
hi, this is unbeleviable, i have a specific question relating to specific
parts , and someone says use XXXX instead , next time they got a question
relating to a SPECIFIC part , i think i might tell them to use something
differant...
**Use the correct part for the job required. An LM317 costs less than a
Dollar.
Fcked up again twevy , answer the question and not try to hide behind
It makes no difference, the parts are fundamentally the same.hi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
Two resistors, it's in many datasheets like here:how can i do this ?
Good idea Ian, I've bodged them up before with just the diodes without probs"K Ludger" <kjlkj@kljl.org> wrote in message
news:491bbb11$0$7531$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
"mark krawczuk" <krawczuk@adam.com.au> wrote in message
news:fbSdnXAo84XsM4bUnZ2dnUVZ_oTinZ2d@adnap.net.au...
hi, i want to make up a 13.8 volt power supply.
i have some 7812 and 7815 voltage regulators.
would it be best to increase the voltage out of the 7812
or
decrease the voltage from the 7815 ?
how can i do this ?
thanks,
mark k
Check out the data sheet Mark, you can add a diode or three in the common
leg to ground to "jackup" the regulator. Diode cathode points to ground,
Each diode will add ~0.6V. Try it & see.
Might be an idea to feed the diode(s) with some bias current via a
resistor to ensure they develop their full Vf - from the output terminal
gives the best stability.
mark krawczuk wrote:
hi, this is unbeleviable, i have a specific question relating to
specific parts , and someone says use XXXX instead , next time they
got a question relating to a SPECIFIC part , i think i might tell
them to use something differant...
'Different'.
You take exception to somebody helping you out by pointing out the exact
right part to be using to do the job, instead of a way to bodge it up
using other parts ? Bizarre.
geoff
What 2 extra parts? - the 317 needs 2 resistors to set the voltage.now , just think about it for a minute you twat , now why would i want
to send away a order for about $15 to get a 1.50 part , ... most places
have a minimum order of 10 dollars , then at LEAST 5$ for postage.....
ummmm i did point out the exact RIGHT PART , a 7812 or a 7815
I DID NOT POINT OUT A LM317 !!!!
PRAYTELL,. HOW IS USING 2 EXTRA PARTS A BODGE ?? I`LL CALL IT
INGENUITY......
"mark krawczuk" <krawczuk@adam.com.au> wrote in message
news:wfednaacmriIFoDUnZ2dnUVZ_gSdnZ2d@adnap.net.au...
now , just think about it for a minute you twat , now why would i want
to send away a order for about $15 to get a 1.50 part , ... most places
have a minimum order of 10 dollars , then at LEAST 5$ for postage.....
ummmm i did point out the exact RIGHT PART , a 7812 or a 7815
I DID NOT POINT OUT A LM317 !!!!
PRAYTELL,. HOW IS USING 2 EXTRA PARTS A BODGE ?? I`LL CALL IT
INGENUITY......
What 2 extra parts? - the 317 needs 2 resistors to set the voltage.
Have to side with TW here, whilst both will work, there doesn't seem to be ahi, this is unbeleviable, i have a specific question relating to
specific
parts , and someone says use XXXX instead , next time they got a
question
relating to a SPECIFIC part , i think i might tell them to use
something
differant...
**Use the correct part for the job required. An LM317 costs less than a
Dollar.
Fcked up again twevy , answer the question and not try to hide behind
bullshite.
so in the Ozzie tradition making do for now..."atec77" <atec77REMOVE@hotmail.com> wrote in message
news:gfioj0$p6p$1@aioe.org...
hi, this is unbeleviable, i have a specific question relating to
specific
parts , and someone says use XXXX instead , next time they got a
question
relating to a SPECIFIC part , i think i might tell them to use
something
differant...
**Use the correct part for the job required. An LM317 costs less than a
Dollar.
Fcked up again twevy , answer the question and not try to hide behind
bullshite.
Have to side with TW here, whilst both will work, there doesn't seem to be a
lot of point in using the wrong part if you can't even read a data sheet and
have to ask for help.
MrT.
read the headers , he appears to be a long way from most shopping malls
That's a good reason of course, but he could have just said so rather thanhe appears to be a long way from most shopping malls
so in the Ozzie tradition making do for now...
**Because he, like atec77, is an ignorant prick. I no longer waste my time"atec77" <atec77REMOVE@hotmail.com> wrote in message
news:gfok9l$fqm$1@aioe.org...
he appears to be a long way from most shopping malls
so in the Ozzie tradition making do for now...
That's a good reason of course, but he could have just said so rather than
abuse anyone offering advice.
I'm still not clear why he didn't just download the data sheet though.
"atec77" <atec77REMOVE@hotmail.com> wrote in message
news:gfok9l$fqm$1@aioe.org...
he appears to be a long way from most shopping malls
so in the Ozzie tradition making do for now...
That's a good reason of course, but he could have just said so rather than
abuse anyone offering advice.
I'm still not clear why he didn't just download the data sheet though.
MrT.
He might take the time to elucidate , but I doubt it