Thanks. I was not thinking about the selector magnet inductance. I was simply going on what worked very well on my 33’s with lest than 25V @20mA

Get Outlook for iOS

From: Jim Cooper <[email protected]>
Sent: Thursday, July 27, 2023 3:04:22 PM
To: David V. Corbin <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: [GreenKeys] Power supply recommendation
 
On 27 Jul 2023 at 18:32, David V. Corbin wrote:

> Is fixed current (or open) so the
> need for voltage is dependent on the
> loop resistance as per Ohms law¦ so
> given that most modern installs are
> oeshort loop (ie often in the same
> room), why the need for something
> that can supply that much
> voltage?????

Look up TIME CONSTANTS in inductive series circuits.

L / R      the L is fixed in the selector magnet
              so the larger the R is, the faster the current
              changes from zero to 60 mA.