GPIO Terminal Block User’s Guide 21
Driving a DC Relay To Control an AC Load
The reader outputs can only switch DC loads, but can drive relays that
control AC loads as seen in the next illustration.
Driving a DC Relay: The external relay provides dry contacts for controlling the
AC motor.
Connecting Devices to the Power Terminal
The power terminal provides access to DC power from the reader
(except for IV7). The GPIO interface provides a total of 12 VDC at 0.5
A for powering external inputs and loads, eliminating the need for an
external DC supply and simplifying the system installation.
Each GPIO interface power has an internal thermal fuse that trips if
the load exceeds 0.3 A, and the fuse is self-recovering once the
excessive load is removed.
The total load on the GPIO interface power must stay within the 0.5
A limit. When you design a system that uses this supply, be sure to
complete a power budget assessment to ensure that the supply is
adequate for the system.
On the power terminal, two posts are available for +12 VDC and
Ground. These posts are tied to each of the +12 V and Ground posts
on the input and output terminals.
AC motor
120-230
VAC
External
relay
-Output, 250 mA max.
Ground
Note: In many installations, the relay and AC wiring must be placed in
an enclosure that meets local fire code regulations.
To Next Page
Loading...
Need help?
General