On Sat, 2007-05-26 at 11:03 -1000, Ken Brown wrote:
> Or if you don't want even the tiny click of a reed relay (someone has
> claimed it is not true QSK if you can hear a relay click) you could use
> an optocoupler. LED in optocoupler only needs a few mA, not enough to
> bother that transistor, and no inductive kickback. Maybe even faster
> than a tiny reed relay.
Typically a lot faster than a reed relay, microseconds instead of
milliseconds.
There are some LED driven couplers that have a stack of photodiodes that
makes enough voltage to drive the gate of a power MOSFET with no other
circuitry on that gate. Made by IRC the last I looked. Probably slightly
slower than the phototransistor output optocoupler.
>
--
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer
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