Differences between revisions 2 and 3
⇤ ← Revision 2 as of 2007-02-15 00:08:28 →
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Editor: bmly-cache-7
Comment:
← Revision 3 as of 2007-02-15 00:10:18 → ⇥
Size: 1083
Editor: bmly-cache-7
Comment:
Deletions are marked like this. Additions are marked like this.
Line 12: Line 12:
                       \ / IN4148 ^ \ BZY88 4v7
                        v diode / \ zener diode		                         ^ IN4148 ^ \ BZY88 4v7
                       / \ diode / \ zener diode

Some PCs serial ports can have levels of -15 volts and +15 volts (while still adhering to the RS232 specification). However, the E3 input circuitry may be designed for levels of 0 volts and 5 volts. If you're feeling protective of your E3, then using the following circuit may put you mind at rest. It works fine for my E3 and mind. 

   PC                                               E3
  9-pin                                           3-pin
D-connector                                     jack plug 

               100R
(Tx) 3 o------/\/\/\----+-------------+-------------o Ring
             resistor   |             |
                        |           \ |
                       ---           ---
                        ^  IN4148     ^ \ BZY88 4v7
                       / \ diode     / \  zener diode
                       ---           ---
                        |             |
                        |             |
(0V) 5 o----------------+-------------+-------------o Sleave

(Rx) 2 o--------------------------------------------o Tip

TheEarthWiki: Serial_cable_for_the_paranoid (last edited 2008-02-19 15:39:25 by localhost)