How do I achieve symmetry thru load

[Zak28]

Simple biphasic oscillator incorporating OPA452 oamps isn't yeilding symmetric ac thru load as depicted in image. Probable cause is zeners lower one cycle by a few volts, but afaik zeners are needed to make the circuit work. Please recommend a remedy to this dissymmetry.




Thank you.

 

[KlausST]

Hi,

but afaik zeners are needed to make the circuit work.

Can you describe why/how two 100V anti-series connected zeners should have an influence in your 38V powered circuit?

Klaus

 

[FvM]

It's surely not the zeners. The simulation results should be seen in the context of previously discussed OP model limitations. https://www.edaboard.com/showthread.php?377089-Why-so-much-power-thru-opamp

I simply won't believe that saturation is correctly modelled here. You absolutely need to check the OP behavior in a real measurement. In case you get asymmetries in reality, think about load AC coupling.

 

[Zak28]

...Can you describe why/how two 100V anti-series connected zeners should...

A potential drop from current conduction.

...check the OP behavior in a real measurement. In case you get asymmetries in reality, think about load AC coupling.

Im glad theres a chance spice errors causing false behavior since Im rather limited in low cost high volt oamp selection. Im sure its spice model at fault since they are prone to errors and also the unlikely case these oamps aren't as decent in comparison to much older parts.