rs485_cable comments

Started by Erik Christiansen, Feb 05, 2008, 06:53

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Erik Christiansen

In the RS232 to RS485 interface converter circuit, the series combination of R9 and R12 is in parallel with the 120 ohm R3, for termination purposes. (Return through C1,C2,C3,C4) The result is a termination under 86 ohms. R13 = 200 ohms would result in a 120 ohm termination, I believe.