T470 Part A User’s Manual © Jed Micro Pty Ltd
Page 8
Screw Terminal 5-way connector (power and relays *)
This allows wiring to the screw terminals of power, IR out / PIR and two screen relays (for Down and Up pulses at the
start and end of a lecture/show)
Connection Function
Wiring
Gnd
Ground
Tx
Screen Down Relay drive *
Rx
Screen Up Relay drive * OR unmodulated IR (0-
>5V) out to CommBox LCD
Res
IR out to an IR Emitter
Res to IR emitter pos, Gnd to IR emitter neg
PIR contact input
Connect PIR NC contacts to Res and Gnd.
Relay-3 FET drive for 12V trigger (5V output) **
Res to Trigger pos, Gnd to trigger negative.
Aux RS232 output
Res to RS232 RX, Gnd to RS232 common
12v
+12 volt input
*
Note:
While we call these outputs “Relays” they are actually solid state (N-FET) transistors whose Source is
connected to the common Ground of the system and Drain to the output terminal. When OFF they are high impedance,
and when ON are like a closed relay contact connecting the terminal to Ground.
The part is called an MTD3055VL:
http://www.fairchildsemi.com/ds/MT/MTD3055VL.pdf
It has an internal clamp
system set at 60 volts, and so does not need an external Zener diode transient suppressor when driving inductive loads.
**Note:
This is a voltage output in this “Relay-3” mode which can drive the gate of an N-FET (such as a MTD3055-
VL) This FET is external to the T470 device.
Connecting an Auxiliary RS232 device – eg Kramer Switcher
•
Res Pin must be configured for IR Out
•
Connect Switcher as shown;
JED
T470
G
n
d
T
x
R
x
R
e
s
1
2
V
8
1
3
4
2
5
1
9
8
7
6
Kramer Switcher RS-232 Port
PAK12-1A
White stripe = neg
+12 V
TX RS232
to switcher
