These two new models have changed architecture and now use 4 parallel driven mosfets with separate op-amps.
The mosfet is the same as the previous models: IRFP264. It is not a mosfet for linear applications and for those who have had models with only one mosfets it has often burned out without being able to reach the declared powers of 150W and 180W.
With 4 mosfets there should be power reserve; 180w become 45W; even with some imbalance the mosfet should hold up just fine.
Too bad, however, that Athorh has mounted 4 tiny heatsinks so they become the bottleneck.
I therefore bothered to change the heatsinks.
First of all I discovered that in this period they cost a lot.
If one wanted to make a nice replacement with 4 dissipators like the original ones with a 4cmx4cm base but 4cm high instead of the 1cm of the tiny standard ones, one would spend 20€ on aluminum and almost double that on pure copper: far too much.
I looked for which one and I found an old-time heatsink 8cmx9,5cm 4cm high and very heavy ... 450gr for only 6€.
And I decided to test it with him.
I tell you right away that it is more difficult than it seems. To fix the dissipator you need precise holes which are then threaded. Furthermore, the base which ends up live (positive) because Atorch has decided to mount the mosfets without insulators for better thermal dissipation, goes over the board and it doesn't take much to damage some tiny tracks that pass underneath or even damage them with the screws you put from 'other side.
In short, attention!!
I tell you that I spent a day on it.
The results are encouraging
with 20 volts 4 A before the modification the temperature was just above 40°C, now we are just above 30°C and this sometimes makes the fan turn off, the temperature obviously rises and the fan start again.
I went to 16v 8 A and the temperature is still a reasonable 41.2 °C, let's say that as soon as I find a more powerful power supply I can definitely go to 150W and maybe even 180W.
With the most suitable heat sinks separated by 4cmx4cm 4cm high (perhaps in copper) you can go even better and the aesthetic result is certainly better.
For the rest, judge for yourself from the photos.
I'll leave the old coolers next to them to give a visual idea of the difference.
Before you ask me about the part of the heatsink that protrudes from the back: I didn't want to cut it; obviously I put some insulator underneath so as not to make short circuits with the tracks intended for expansion.