[GreenKeys] RS-232 to Polar Relay

[Bill Abate]

You might be able to drive a polar relay with RS-232 output but it 
probably won't work well.  The typical 255A polar relay should be fed 
with 100-120VDC with a dropping resistor to get your 60 or 20 ma loop 
current.  Otherwise there is quite a bit of bias, etc. Its all about 
back emf.
73,
Bill, K3PGB
 > Message: 5
 > Date: Mon, 16 Jan 2023 13:37:41 -0500
 > From: Tom Hunter <tomhenryhunter at gmail.com>
 > To: GreenKeys at mailman.qth.net
 > Subject: [GreenKeys] RS-232 to Polar Relay
 > Message-ID:
 > <CAJK8693Y0eAPQfoFUSq4m5pfjGV0ADO64fwvWdxuFagQc+EMbA at mail.gmail.com>
 > Content-Type: text/plain; charset="utf-8"
 >
 > John,
 >
 > A while back someone (and I cannot remember whom, because he deserves the

- Ignored:
 > credit.) Mentioned that a polar relay can be driven directly by an RS-232
 > output. Think about it, it is really a polar signal.
 >
 > I am kicking myself because I never thought of something so obvious.
 >
 >
 > Tom N3CRK
 > *****************************************

- Done.

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