[sdiy] ML317: 12V to 10V?

[Stewart Pye]

Hi Mykolas,

You need a 10 V reference rather than a 10V regulator.
Have a look at the LM4040 and REF01.

The voltage reference will have minimal drift with temperature. This is 
one circuit where you want reliable accuracy. I'd be using an op amp 
with low offset voltage and low drift.

Changing the value of the resistors to 100k would actually decrease 
accuracy as there will be more loading by the op amp input. 10k looks 
like a reasonable value. If you want more accuracy use 0.1% resistors.

Regards,
Stewart.


Mykolas wrote:
> Hi all,
>
> I'm building up VCO scale adjust tool (see idea:
> http://electro-music.com/forum/viewtopic.php?p=307414#307414 ), and
> thinking of
> precise 10V reference (I can go down to 7V, no big deal), but I can
> get only 12 pin
> rotary switch, so extra pins with ref voltage will be in good use in future :)
>
> I don't want it to adjust ref voltage each time I'll use it, so in
> this case stable voltage to op-amp suits me.
>
> I've got plenty 12V 100mA DC wall wart power supplies and wish to use
> it in this project. I can dismantle it and use only transformer and do
> other things by myself.
>
> I'm thinking to use LM358D instead of TL082.
>
> Other thing is: Can I change 10k 1% resistors to 100K 1%? More acuracy
> I suppose?
>
>
>
> 2010/9/16, David G. Dixon <dixon at interchange.ubc.ca>:
>   
>>>> Can I use LM317 voltage regulator to have +10V out of +12V? (2V
>>>> difference) Can't find on net.
>>>>         
>>> It may work, although 2V is a bare minimum Vin-Vout difference for the
>>> 317.
>>> How much current are you requiring on the 10V side?
>>> You might consider a low-dropout (LDO) regulator if that is an option.
>>>       
>> What's your application?  Are you sure you couldn't just divide down to 10V
>> and buffer with an opamp?  Or, if a precise 10V reference is what you are
>> after, but not much current (< 10mA), something like REV102 might be more
>> appropriate.
>>
>>
>>     
>
>
>