Please recommend a buck/boost module to connect to a 90W laptop power supply

[FBMinis]

Something like this? https://www.aliexpress.com/item/1005003820144742.html

If possible, I'd rather get one of these modules and use a laptop brick to make a regulated power supply. Something to test my arduino/esp8266 projects, stuff with 12V motors, etc.

There are so many options out there and they all seem to do the same but prices vary quite a bit.

(not sure if this is the correct forum subsection)

[liaifat85]

Could not access the link. Don't know why.

[Shonky]

Link works fine but best to include the non language specific link IMO otherwise AliExpress gets carried away changing the display language everywhere which is annoying....

https://www.aliexpress.com/item/1005003820144742.html

Something like that will probably work, but like most things AliExpress, your mileage may vary. Read reviews. Look at the customer photos. Look for versions that have the highest number of orders. I can't recommend specific ones but I see that same basic design is sold by many sellers, so read the reviews.

Supply could be noisy or oscillate or not handle transients very well.

[LinuxHata]

I had this.
It works, sort of.

There are two issues:

1. 4A output current is very optimistic approach. Even at 2A load, making 5V from 19V (laptop supply), will make output diodes to go around 125C and above within couple of minutes. I'd say that 1A is an all-purpose current which you should aim to with this module. Of course, when input-output voltages are close enough, you can juice a higher current.

2. When the load is non-linear (LED) and you have CC mode enabled, the output voltage will self-oscillate, starting around 10hz (depends on output current)

Conclusion: Look elsewhere.

Same applies to similarly featured, but with color screen, FNIRSI branded modules.