[GreenKeys] Loop power supplies

[Ralph Mowery]

I and others have tried it, and 24 volts and under does not work even on short loops ( like maybe 5 or 10 feet of wire)  with machines like the model 15 printer.  It really needs more than 50 volts to do the job, close to 100 or 150 volts to really work well.

 

It is not the length of the lines, but the high inductance of the model 15 type coils.  I have not worked with the more modern machines like the 32 that seem to have a built in supply for the printer, and they may work very well on the low voltages for the loop supply.

 

From: greenkeys-bounces at mailman.qth.net [mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of drlegendre .
Sent: Saturday, March 03, 2018 10:49 AM
To: epvgk at limpoc.com
Cc: Green Keys
Subject: Re: [GreenKeys] Loop power supplies

 

120V at 4A.. good grief that's overkill. 

 

Bear in mind that the 120v / 60mA spec is for running very long loops, like on the order of miles. Running a loop around a room or even a whole house should be possible with a 12V or 24V wall-wart (and 200R / 400R resistor). That high 120V spec is to deal with the inductance imposed by long lines. You don't actually need anything that high for short runs. 

 

Try it. 

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