can you run the HP 55 on AC adaptor without batteries?

[Steve Simpkin]

(02-28-2021 11:44 PM)dmh Wrote:  

(02-28-2021 11:31 PM)Steve Simpkin Wrote:  Yes. Running the Classics on AC power without a battery pack is safe. The AC power supply on these models has a separate regulated power source for the calculator logic.
There was some concern about doing this on the HP-67 (which is not really a "Classic") but it appears safe on those as well. More information here.

https://www.hpmuseum.org/forum/thread-82...l#pid72353

Regarding the 55, thanks!

Regarding the 67, I read that thread you shared (thank you) and am still confused about the 67. Towards the end it seems to go back to saying don't run the 67 without a battery.

Yes I read that too and edited my post. As per the manual, do *not* use the AC charger on the HP-65, HP-67 or HP-97 without the battery pack installed. Of course this is also true for any of the Woodstock or Spice models. Sorry for the confusion.