Hi,
The attached file doesn't finish simulation unless I keep pressing ESC to view the results. Plus, you seem to use the "AC analysis" tab which I still don't know about it much other that bode plots of output vs feedback for each loop to check for zeros and poles. Perhaps this is how you picked the values for feedback resistors and caps? my concern is parts consolidation which is like using 1nf or something a lot rather than odd values that are used once for one thing. Is that possible in your circuit?
* transients:
Hmm is this by just transient response alone? like watching the time needed to switch between CC and CV? what danger does low currents do to this circuit? my guess is that CC will be pulling the output mosfet down a lot to achieve low currents... which might be bad for CV part as you said. Is this correct?
* Testing:
right now I don't have any of these parts, especially the mosfet and the npn controlling its gate. You choose 240p rather than 250p so I dunno if the bigger cap 250p will work nice or not, since it is more available i guess.
One bad thing is the op-amps! too expensive and won't be available unless you get them from digikey or any other official distro. I wanna choose other cheaper op-amps but I fear that the circuit will not work after all these efforts. EEZ-Supply uses TL07 op-amps but they have no LTSPICE models!
* extra current limit:
is this the same one as this image (eez-supply):
well, now I will use another 10 resistors (1 ohm value) to get this shunt res, let alone the switching regulator which must have it's own shunt res as well xD. 30 smd resistors are dirt cheap but takes place... lots of space xD. This is not a big problem though.
* "With a good CV -CC crossover (capacitor from behind the diodes)"
??
* "The capacitors for compensation of the CV modeare chosen iterative from the AC output impedance. R20 a little larger than R23 and so that R20*C4 is about R23*C11 to avoid another time constant."
You got all that from the AC analysis or what exactly (same as my first paragraph)?
if this will be a final circuit, then why not choose the values of R20,R23,C4,C11 to be the same since it is the same gain? is the reason for differing them that the value of R8 and R9 is not the same?
* "C1 started larger and was reduced until the curve looked good. The Transient response turned out to be ok from the beginning (as I new what the output impedance about has to look like)"
you mean the response time vs stability? bigger caps = more stable + longer time?
the stuff about knowing output impedance and curves is related to the AC thing I asked about so I won't repeat the question xD.
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I learned that I must do AC analysis for all loops whenever I do stuff... to make sure I know what to do. this thing is new to me really, so it will be hard to learn... I just need to know what to do so I can know what should I learn.
always thanks for responding... always!