Re: "Barrel" connectors

On 6/16/2025 10:07 AM, KevinJ93 wrote:

Some Dell notebook power supplies have used that approach.
 The barrel consists of two concentric cyclinders with the outer being the negative connection and the inner one being the positive supply. The pin directly connects to a OneWire Dallas Semi/Maxim memory that has the power supply ID.
 The computer can then interrogate the power supply to determine current capability and that it is a genuine Dell supply.
 My first exposure to one resulted in me destroying the supply!
 There was no protection for the memory device and I accidentally shorted the centre pin to the inner barrel when attempting to measure the voltage output.
 The 19V from the supply destroyed the OneWire memory. Whenever the PSU was plugged into the computer it would not identify it as a Dell supply and would not charge the battery and would only run at reduced speed.
 It is not obvious that the outer barrel and inner barrel are not the same connection.
 Be careful with Dell supplies. Modern ones may be different this is from ~15 years ago

Dell "desktop" supplies have similar quirks -- "wrong" pinouts, etc.
Most of the machines that I run have very *specific* power supplies;
nothing else will mechanically fit.  This still leaves me at the
mercy of the vendor having a different (mechanically compatible) supply
for one model than another.
I pull compatible supplies, label them and toss them in a "parts box"
labeled with appropriate device's name.  (Repairing power supplies is
just not a good use of my time; easier to just horde spares!)