Looking for help understanding how this discrete design works.

[Momomo391]

There may be a mistake that Q1 and Q78 could be NPN transistors with their bases and collectors flipped from how they are in the photo but im not sure. Any help is super appreciated! I believe this is suppose to act as an expo converter but im confused on how it works or if the schematic is off??

[magic]

The upper part is a simple opamp wired for unity gain. The lower part is certainly wrong, inputs generally don't go to collectors nor do outputs come from bases. There is no source of base current into T30, so something surely is wrong with polarities of D5 or T24, or other components are still missing.

[Momomo391]

Would it make more sense if Q1 and Q78 were NPNs and had their collector and base connections swapped??

[T3sl4co1l]

No, the problem is diode polarity vs. T24 collector. Both are sinking current.

Q78 base doesn't make any sense for output.  T38 emitter perhaps makes more sense as an output, or T23 collector.  That's not to say a dependent current won't be available from Q78 base, but it's a strange way to do things if so.  With a completely anonymous "Output" (and "Input"), and no mention of application, we have no way to evaluate whether that's how it's being used.

Tim