> I want/need to design a power supply (13.8VDC @ 20-25 Amps) to run my
> Amature Radio equipment with.  It needs to have GOOD filtering.
> Switching-type OK, but need to avoid "whine" or "hum" when transmitting.
> Any good websites out there with thoery/design of power supplies?
>
Hi Duane,

From Experience this is a lot more difficult than it first appears.

1.  There are a lot of designs out there which can be adapted from others
intended for other applications. Look for 300 watt supplies. For a one off
the costs will shock you if you intend building with new components.

2.  Crap from the power supply will prove to be an easy problem to solve in
comparison to crap from the transmitter getting into the PSU and upsetting
the control loop (I am assuming worst case here and you are operating on hf,
personally I wouldn't be see dead operating on frequencies I can whistle
at :-) ). Plus there are all the safety aspects in dealing with a primary
side controller.

3.    My recommendation would be to design a low current supply and battery
charger. The low current supply covers the receiver operation and the
battery provides the high current demands of the transmitter which is
recharged during the receive periods (and the times you are out of the
shack). Batteries are easy to obtain and cheap (Yorkshire Yammer roughly
translation... free) at your local tyre and battery establishment. Look for
batteries removed from lorries. These are usually replaced because they are
no longer capable of supplying the current necessary to start a lorry engine
reliably, but float charging and used to supply the transmitter current
demands in amateur service they are good for at least a years use. Then you
take it back and swap it for another

Regards

Chris

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body