Re: Neat power supply!
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Most AT and ATX style computer power supplies are shielded by the metal case. They do lack
shielding in the form of bypass capacitors on the DC leads leaving the case. This can be fixed
by installing 0.1 mfd capacitors on the DC leads as close as possible to where these leads pass
through the metal chassis.
Laptop type computer power supplies are a little different because they are designed to charge
batteries and not for directly running devices that have rapidly varying loads. It is usually possible
to remove some of the RF interference from these units by adding 0.1 mfd on each DC lead, but
the plastic case is the real problem. Some luck has been had by removing the plastic case and
installing the PCB inside a metal case, with appropriate input and exit RF bypass arrangements.
Switching power supplies that are designed for constant load can sometimes be made to work
with varying loads by adding 2200 or 4700 mfd capacitors across the DC outputs. These
capacitors can usually be found and salvaged from dead or unneeded AT or ATX style PC power
supplies. This might be a good tactic for laptop type power supplies that don't quite have enough
current on peaks to handle the varying load of an SSB or CW transceiver.
On Sat, Jun 30, 2018 at 10:56 AM iz oos <and2oosiz2@...> wrote: