On Tue, 20 Feb 2001 09:33:10 -0500, Mike Murphy wrote:
>Larry,
>I can only speak to question 1. It sounds like your reed switch is being
>damaged by arcing when there is a near lightning strike. That's not
>unusual given the length of rotor cable and the relatively low breakdown
>voltage of reed switches (just a few hundred volts). That being the case,
>you should get excellent protection by paralleling a suitable varistor
>(MOV) across your switch(s). You want a part whose standoff voltage is
>higher than the normal open circuit voltage found across the switch but
>whose clamp voltage is lower than the breakdown voltage of the switch.
>A suitable part could be Digikey P7240-ND (Panasonic ERZ-V05D101)
>or Digikey P7252-ND (Panasonic ERZ-V10D101) which is physically a
>little larger but can disipate much more energy. These selections are
>made on the assumption that your switch open circuit voltage is well
>below 100 volts.
>
>73,
>Mike, WA4BPJ
Thanks for your excellent idea Mike.
I'll try to find the part - maybe Mouser.
Larry Alkoff N2LA - Austin TX
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