Re: How do I convert 0-10V to -5V +5V differential?

On 31 Aug 2005 13:13:19 -0700, kasterborus@xxxxxxxxx wrote:

>Thanks for you all your help - I have all the parts to build the op-amp
>solution at home - the only thing that puzzles me a bit is the
>+15V/-15V power to the 741 - how do I create +15 and -15V from a
>standard transformer.

---
Since the 741 can take an input supply of plus and minus 22 volts,
max, you can easily get less than that that from a simple,
unregulated, half wave supply using a 12V transformer, like this:



+--[IN4001>]----------+---->+17V
| |
| |
MAINS>--+ || +--[<1N4001]--+-------|---->-17V
| || | | |
P || S | |+
R || E [C1] [C2]
I || C |+ |
| || | | |
MAINS>--+ || +-------------+-------+---->GND



Since your output is only going to swing between +5 and -5V, and the
741 needs about 3V above and below that to let that happen, you've
got about 9V of headroom to either rail so C1 and C2 can be fairly
modest, depending on what else you're going to use the supply for.

What can you tell us about the load?

--
John Fields
Professional Circuit Designer
.