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From: Richard Torrens (News) on 27 Jun 2010 05:29
Several circuits are at
http://www.4qdtec.com/csm.html Current sources and mirrors


You will find somethoing suitable there !

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From: dwight on 28 Jun 2010 17:57
On Jun 24, 9:30 am, panfilero <panfil...(a)gmail.com> wrote:
> can anyone offer any suggestions on how to make a simple 4mA current
> regulator... I started looking at LM317 voltage regulators, but found
> that they're gonna output a minimum of 10mA... I'm now looking at
> JFETs with a resistor between the source and gate... most the JFETs
> I'm finding can only provide currents less than 3mA...
>
> thanks

Hi
Depending on the dynamic range of the voltage, you could put
a resistor from the output lead to ground to supply a minimum
current.
If the voltage range was high enough, you could even use a second
LM317 as the minimum current. Sink enough extra current in
the second regulator to keep the first one in range.
My reading of the spec is that
5ma is the worst case minimum and not 10ma.
Dwight
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