A positive peak detector circuit

[FOIWATER]

For anyone interested, the attached circuit performs to spec, uses both an AD829 and LM318 with the same basic config as discussed.

Any one have any possible improvements?

(The main drawback I was not considering was compensation caps for the op amps, which I got from the data sheets)

 

[meBigGuy]

Looks pretty cool. Post some waveforms.

Are you saying the 829 compensation solved the slew rate problems?
I have questions (curiosity).
Why the resistor in series with the main storage capacitor?
What does R5 do? (looks like it is just across the supply)?
What does C6 do? How did you choose that?

 

[FOIWATER]

Ill take some pictures of the oscilloscope I have made the circuit it works, pretty decently. Perfectly in the simulator but, yeah.
Yeah there is absolutely no slew rate problems with this circuit what so ever. but notice it is being driven at unity gain. The 829 is one of the fewer than 5% of op amps without unity gain compensation. As such it requires external capacitors to ensure it doesn't go unstable. (the stair-casing we saw earlier at unity gain). Usually the compensation capacitor is placed from pin 5 to ground but it worked really good here.. I am still trying to find out why by looking at ad's blog this helped a lot http://www.analog.com/library/analogdialogue/archives/38-06/capacitive_loading.html

R5 is actually a resistor on the output of the 829 which shifts the pole of the op amp due to the internal capacitor. It allows for higher bandwidth

R5 just keeps the simulator happy. adds no real effect when breadboarded. Just something I picked up from using multisim

 

[FOIWATER]

(also R5 is not connected to the positive rail, it's from the pins to the negative rail I know it looks like it is though)