[GreenKeys] Loop supply voltage

[Ralph Mowery]

No, the distance does not matter.  It can be one foot and the high voltage will still be needed.  
What happens is the inductance of the coils has a time constant.  That is the coil acts like an open circuit when the loop is first closed.  Then a fraction of a second later it will act like a very high resistance and each fraction of a second the resistance will be reduced to it finally reaches a steady state of low resistance.  While not technically correct that is what happens.  It is the opposite of a capacitor charging where the capacitor acts like a short circuit and then the resistance gradually rises as the capacitor charges.

Ralph ku4pt


-----Original Message-----
From: greenkeys-bounces at mailman.qth.net [mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of E.
Sent: Saturday, January 18, 2025 11:17 PM
To: Anthony Watson via GreenKeys
Subject: Re: [GreenKeys] Loop supply voltage


I could be going off onto the wrong rail here, but sometimes those loops had to travel over good distances, so they needed the higher voltage in order to keep the “signal" over the line from degrading….. right?