Diff for "Serial_cable_for_the_paranoid" - the.earth's UK Tech wiki

Differences between revisions 1 and 2

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
                        v  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)

-  ⇤ ← Revision 1 as of 2007-02-15 00:06:27 → 
  Size: 1081
  Editor: bmly-cache-7
  Comment:
+   ← Revision 2 as of 2007-02-15 00:08:28 → ⇥
  Size: 1083
  Editor: bmly-cache-7
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
-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.
+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.