Externally Powered Relay - Polycom SoundStructure C16 Hardware Installation Manual

Hardware Installation Guide for the Polycom SoundStructure
This example circuit uses an Omron G5CA relay and the coil resistance is 125 ohms. Because of this coil
resistance, an additional series resistor is not required to limit the current from the 5 V supply to less than
500 mA in this example.
SoundStructure Powered Relay
Pin 1 : +5 V
Pin 2 : Logic Output 1

Externally Powered Relay

SoundStructure can be used with externally powered relays when the following conditions exist:
● The relay is DC powered.
● The DC voltage does not exceed 60 V.
● The current from the power supply and relay circuit does not exceed 500 mA.
Externally Powered Relay
External +12 V
Pin 25 : Ground
- +
Pin 2 : Logic Output 1
Remote Control
As with the 5 V relay example, when the logic output pin (Pin 2 in the above example) is set on (1 or high),
the relay energizes and the relay contact is closed. When the logic output in is set off (0 or low), current
stops flowing, and the relay de-energizes and the relay contact is opened.
A diode is recommended to be placed in parallel with the relay to provide a path for the discharge of the
magnetic coil of the relay. This current will discharge over a very short period of time and a diode capable
of handling a large amount of surge current such as the 1N4001 is recommended and is available from
several manufacturers. The 1N4001 is rated up to 50 V, if higher voltages are required, the 1N4002 is rated
to 100 V.
This circuit uses an Omron G7L 12 V relay with a coil resistance of 75 ohms. For this reason, an additional
series resistor between the power supply and relay is not needed to ensure the current from the 5 V supply
is less than 500 mA.
The ground connection of the power supply must be connected to the ground pin of the logic connector (Pin
25) in order for the return currents from the external power supply to be able to return to their source.
Polycom, Inc.
5 V Relay
External
Device to
be
Controlled
12 V Relay
External
Device to
be
Controlled
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