This circuit can be used by 'CT' (and others) to key the transmitter
from a serial port:
+-----------------------+
| Radio Shack TIL-113 |
| |
+---+ +---+
| | | |
To RS-232 Signal o-----+ 2 +---+ +----------+ 6 +-o NC
Ground (Pin 7 of DB-25) | | | | | |
(Pin 5 of DB-9) +---+ | | +---+
| | | |
| --- | |
| ^ | |
| / \ | |
| --- | |
| | | |
| | | |
D1 | | \ | |
+---+ | \ | +---+
R1 | \| | | | \ | | |
To RS-232 o--+-/\/\/--+ >--+ 1 +---+ \ | +---+ 5 +-o To
DTR (Pin | | /| | | | | | | Positive
20 of DB-25) | +---+ | | / +---+ Keying
(Pin 4,DB-9) | | | |/ | Line
--+-- C1 | | | |
--+-- | | | |
| | +---+ |
| | | |
| | | |
| | |\ |
To o--+ | | \ |
Computer | +---+ _| +---+
Chassis | | | | | |
Ground --- NC o-+ 3 | +--+ 4 +-+-o To
- | | | | Xmtr
+---+ +---+ Chassis
| |
| |
+-----------------------+
D1 = 1N914 or 1N4148
R1 = 1K Ohm, 1/4 Watt
C1 = 0.01 Microfarad, 50 Volt
DTR = Data Terminal Ready pin
NC = no connection
Note: Voltage on pins 4 and 5 of TIL-113 should be kept below 20
volts, and the current draw should not exceed 100 ma.
----------------------------------------------------------------------
This circuit can be used by 'CT', LOGic-4 (and others) to key the
transmitter from an LPT port:
+-----------------------+
| Radio Shack TIL-113 |
| |
+---+ +---+
| | | |
To DB-25M o-----+ 2 +---+ +----------+ 6 +-o NC
(STROBE) Pin 1 | | | | | |
+---+ | | +---+
| | | |
| --- | |
| ^ | |
| / \ | |
| --- | |
| | | |
| | | |
D1 | | \ | |
+---+ | \ | +---+
R1 | \| | | | \ | | |
To DB-25M o--+-/\/\/--+ >--+ 1 +---+ \ | +---+ 5 +-o To
Pin 17 | | /| | | | | | | Positive
(SELECT- | +---+ | | / +---+ Keying
INPUT) | | | |/ | Line
--+-- C1 | | | |
--+-- | | | |
| | +---+ |
| | | |
| | | |
| | |\ |
GND o--+ | | \ |
DB-25M +---+ _| +---+
Pin 18 | | | | |
NC o-+ 3 | +--+ 4 +-+-o To
| | | | Xmtr
+---+ +---+ Chassis
| |
| |
+-----------------------+
D1 = 1N914 or 1N4148
R1 = 1K Ohm, 1/4 Watt
C1 = 0.01 Microfarad, 50 Volt
NC = no connection
1) Note: Voltage on pins 4 and 5 of TIL-113 should be kept below 20
volts, and the current draw should not exceed 100 ma.
2) The SELECT INPUT is the LPT signal name, it is really a PC output
and used as a source of 5vdc to turn on the LED in the Opto-isolator.
--------------------------------------------------------------------
My thanks to Glenn, AE0Q for the above information.
Frank, G3YCC