[sdiy] inverting active clamp??

[media at mail1.nai.net]

Is it possible to build an inverting active clamp from a single op-amp such
that Vin = - Vout for positive voltages from ground up until the clamping
voltage??  Little slewing glitches are OK, those can be filtered with a cap
-- the expected input signal is single-sided and relatively slow moving.

I don't know, but I've been told, the ascii circuit below produces Vin=Vout
for Vin below +10V:



                  diode
              +----->|----+----- output
              |           |
        2K    |           |
input--/\/\/--+--(-)-|\   |
                     | >--+
              +--(+)-|/
              |
              |
+15Vcc--/\/\/-+-/\/\/---+
          5K    10K     |
                      ground

Does that look right??  I'm not sure how the 2K value is derrived.

Anyway, I'm looking for the inverting circuit.  I want it to clamp at +5V.


Thanks to everyone who answered my bare copper question.  Sorry, I don't
have the MN3214 data sheet -- I looked.