BTW would a new thread in the project section would be more appropriate?
If you plan to implement and verify your design in hardware... maybe yes. Otherweise it makes not much sense.
There is almost nothing special in your design... emitter folower and 2 error amplifiers. LT1013 is also strange choise, since it is quite slow and has odd pinout for dual opamp.
The only thing i liked, is usage of Sziklai pair instead of Darlington.
just my 2 cents
I do plan to build the real circuit.
I showed just the simplified one, but I've been running thousands of simulations on this kind of circuit (with models of real parts) in order to check all the possible conditions (voltage/current control loop gain stability, start-up, switch-on/off, remote sense, fine/coarse regulation, short-circuits, master/slave tracking, transformer-tap switching, etc.)
LT1013 speed is more than adequate for a power supply, and in particular mode for a beginners' one.
In any case I'll be glad to know about any other faster opamp with the following features:
- cheap and easy to find as LT1013
- possibly in DIP package (some old guy like me cannot struggle with those small SMD arthropods
)
- low voltage offset/drift
- maximum supply voltage >= 44V
- ability to work with input/output at least close at one of the supply rails without phase reversal
- and yet I might have forgotten something
So please suggest one.
The most funny thing is the hint to the "odd pinout" of LT1013... I just checked... most dual opamp I got here are the same:
AD8066, LM358, TL0*2, MC3**02, microchip ones, NE5532... and so on... You must be kidding
BTW I just noticed you suggested the usual bad ebay kit.
That is one of those ugly circuit design I was referring to.
While in most cases TL071/4-TL081/4 do work with input voltages close to the positive rail they are not granted to do that.
E.G. for ±15V supply the datasheet grants only ±11V of input voltage range and AFAIK there is no mention about phase reversal protection.
Besides that TL0* output range is much more limited than that of LT1013 (3V less than supply rails) and so is the maximum supply voltage.
I would not comment further on that other
weak design choices as that was already discussed here in past.
Advantages of the circuit I propose (some are evident only in the completee circuit I show later):
- it is cheap and yet offers much better performance than many other circuits you find on the net
- it is simple to understand and to build for a beginner
- needs only one transformer winding
- no need for an additional differential amplifier (only one opamp in the loop of the current control)
- the current control reference is supplied by a basic constant current circuit that also works as down-programmer without loading the current sense resistor
- the ability of LT1013 to work with voltages close to the negative rail allows a really low dropout
- probably the cheap dual V/I panel meters sold on ebay would fit easily and might even be used directly for the current sense (unfortunately I do not have one here to ckeck)
Of course
I'm not pretending that it is the best circuit.
There are much better circuit using more parts and separate rails for the control circuit (Harrison's design) widely discussed, for instance, in the HP's DC power supply handbook.