sim of "voltage regulated PSU" PUBLIC

In your post:

https://www.circuitlab.com/circuit/9bf977/voltage-regulated-psu-triple-darlington_v-protect/

you said:

"Any mods you can suggest are welcome"

and in:

https://www.circuitlab.com/circuit/wsqm3b/moving-magnet-coil-pre-amp-using-op-amps/

you said:

"If anyone has some improvement to mention please make a comment."

Since you have removed all my comments - made in good faith and in the spirit of increasing everyones understanding of some aspects of electronics design - on those postings as well as those on:

https://www.circuitlab.com/circuit/44shk4/ultra-low-noise-pre-amp/

you have thereby removed any context in which to set my simulations and comments therein of your circuits.

Apart from stating in the now deleted comments that all the zeners in:

https://www.circuitlab.com/circuit/9bf977/voltage-regulated-psu-triple-darlington_v-protect/

are all the same, you have not offered any further information about what component values you have used in your real circuit.

It is therefore somewhat unhelpful to assert that:

"Your Caps 10uF is far to low a value to be a (stable) Reg-PSU I"

particularly since:

(a) I have already made the point in my example that the nonlinear effect I have illustrated can be "hidden" by increasing the size of the various decoupling capacitors in your original circuit;

(b) although the frequency response plot shows peaking at around 100kHz, which would again be solved by appropriate sizing and modelling of the capacitors, for which you have given no information, this peaking is 3 orders of magnitude higher than the frequency at which I chose to demonstrate the effect of the output nonlinearity.

However, since you have also blocked me from commenting any further on your designs I would be grateful if you would restrain your use of sarcasm in yours on mine.

@jonnyaudio,

"I also calculate your output voltage to be 45.5Vdc"

Your calculations agree pretty well with the simulation.

"using a 400ohm resister to drop the voltage over a zenner which which only requires 10mA is potentionally dangerours for the circuit builder."

Reducing the zener current from 20mA to 10mA is not really enough to reduce the device power dissipation sufficiently to guarantee they will not catch fire in a practical circuit.

The current I chose was almost entirely arbitrary since my simulation cannot catch fire.

A zener current of 20mA happens to neatly illustrate the nonlinear effect.

As I have already said you put no values into your original post. My simulation is therefore to illustrate a point and not to recreate your original circuit from guess work.

You are most welcome to play with my sims, putting in the component values and their associated parasitics etc. that you have used.

If you look at how I have calculated the series resistors feeding the zeners, you will see I have used an expression based on the nominal voltage drop across the resistors and the current through the zeners.

Reducing the zener current to approximately 2mA each, whilst leaving everything else unaltered, moves the nonlinear steps in your design around but does not significantly affect the underlying behaviour.

"I still think you do not know what you are doing just copying other peoples circuits then telling half truths to people on here..."

You have removed all my comments on your original postings - and I have no intention of rewriting them all here - so readers have no context in which to evaluate your opinion.

You are of course entitled to your opinion but rather than effectively censor all discussion prior to this point, it might have been more sensible to add your own comments to mine and let viewers, both in the CL community and the wider EE world, play with the sims, read the discussion, think it through and then make their own informed, evidence based decisions.