Vip Input Connections; Figure 3-1. Relay Coil; Table 3-2. Vip Input Connections - Motorola ASTRO XTL 2500 Installation Manual

3-2
When installing relays to the VIP OUT lines, a diode is necessary to prevent damage to the transistor
or MOSFET, due to "back EMF" when the field collapses on the relay coil. Some vendor relays
already come with this diode built-in, and other relays require the customer to install it.
shows the proper placement of the diode across the relay coil. The transistor or MOSFET is located
inside the radio or the D.E.K. box.
NOTE: See Appendix A: Replacement Parts Ordering to order relay's for your VIP OUT applications.
Example relays used are TLN4533 and HKN4258.
3.1.2

VIP Input Connections

The VIP input pins are only available on the back of the control head. These connections control
inputs from switches. One side of the switch connects to ground while the other side connects to a
buffered input on the control head. The switch can be normally closed (NC) or normally open (NO)
depending on the configuration of the VIP inputs. There are three VIP input connections, as follows:
VIP IN #
1
2
3
October 12, 2005
Protection
Relay
DIODE
(back EMF Coil
protection)
Transistor or
MOSFET Driver

Figure 3-1. Relay Coil

Table 3-2. VIP Input Connections

J400
On/Off
Ground Pin
Switched
Number
Pin Number
2 (green) 8 (white)
2 (green) 9 (orange)
2 (green) 10 (violet)
Options and Accessories Installation: VIP Overview
SW B+
N.O.
N.C.
VIP OUT
Line
GND
J2
On/Off
Ground Pin
Switched
Number
Pin Number
NA NA
NA NA
NA NA
Figure 3-2
HLN6923A