Kevin, Not to worry. The great advantage of a switching power supply is that it will operate on any AC or DC input, of any frequency or waveform. A linear power supply, in stark contrast, must be designed for the particular input voltage, frequency, and waveshape. The CATV power supplies are probably switchers, for precisely that reason.
73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Kevin Custer Sent: Sunday, February 14, 2010 5:43 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] 85VAC to 12 VDC? Eric Lemmon wrote: > AJ, > > The obvious solution is to connect a commercial switching power supply- > definitely NOT a linear supply- across the AC source. Most Samlex, Astron, > and DuraComm switchers can work wonders in such an environment, where > conventional linear power supplies will surely fail. Don't use a larger > (higher capacity) power supply than you really need; in this case, larger is > not better! Be careful here... The output of a CATV power supply is not a sine wave. I'm not sure how these commercial switchers would react to the AC available from the CATV line. Certainly while switching supplies are used in the CATV industry to power the amplifiers, nodes, and telemetry, I don't know if they are made exactly like the ones fed from commercial AC. It would be much better if he uses a power supply intended to be connected to the CATV line. These can be scavenged from working surplus CATV equipment. Several of the ones I'm familiar with can supply an amp or two at 24 VDC, and that used to feed a regulator or charging circuit for 12 volts. Kevin
