[RFI] Multi-Stage High Efficiency Air Conditioner Units

[Rob Atkinson]

>for example, they don't affect rise times that can seriously increase dissipation and cause equipment failure. Capacitors and inductors applied to the differential circuit CAN cause problems by >affecting rise times.

Not everything is dependent on some tightly defined rise time.   I
have a DX Engineering NCC1 phasor box here that had chattering relays
inside whenever I operated on 160 m. with a 300 watt carrier.  It had
bypass caps on the DC T/R switching line.  I put a pair of small pie
wound chokes in series with the + and return lines at the box's keying
jack and that fixed the problem.   Oh sure I could have spent $20 or
$30 on a bunch of material 31 or lower frequency snap on cores and
wrapped a bunch of line turns around each one and solved the problem
that way, but if you know what you are doing, you can effect a much
more elegant solution with a pair of 50 cent chokes.   It pays to look
for little chokes at hamfests and pick them up as they have a lot of
uses.   Note however, that this example has nothing to do with square
waves in a PDM speed control on a motor which may indeed require a
sharp rise time.

73
Rob
K5UJ