[aprssig] backup pwr systems

[VE7GDH]

Ben VK5JFK wrote...

> What sort of backup power systems do people use these days? eg.
> Running a rig from a standard PSU while charging a battery at the same
> time and when the mains power drops out the battery will take over and
> run the radio. Then when the mains power is returned every thing is back
> to normal, battery is charged again from PSU and radio runs from PSU.
> Any body have any ideas on how to work this or has a circuit that I can
> build

There must be lots of variations. West Mountain Radio has what they call a
PWRgate. It consists of a couple of 80 amp Schottky diodes and some other
circuitry to keep your battery charged. It acts as an OR gate to isolate the
battery and power supply from each other. The forward voltage drop of less
than 0.3 volts at 20 A. When the AC fails, the battery takes over
seamlessly. The power supply should be adjusted to a slightly higher voltage
than normal to make up for the small drop across the diode. They say that it
is a four stage charger ideal for gelled or AGM batteries and can be set to
charge at a 1, 4, 7 or 10 Amp rate. I'm sure there are lots of batteries out
there just floating across a power supply with no proper charging circuit.
The PWRgate does a pretty good job and is better than nothing. I have a
couple of these ahead of Rig Runner "power bars" also from West Mtn.
Radio. Ahead of everything I have a 3 KW true sine wave inverter and a
large battery bank, but I'm powering a bit more than a radio & a TNC.
This is backed up by a 2 KW "inverter" type generator that also puts
out a clean sine wave to keep things ticking along if the power is off for
more than a few hours. Some people have solar panels and a proper
charge controller to maintain their backup batteries. I'll probably add
these some time in the future.

73 es cul - Keith VE7GDH
--
"I may be lost, but I know exactly where I am!"