Ramsey Electronics URC1 Owner's Manual page 17

place of the pot presently in a circuit with this method of squelching. Also good
in voltage divider networks, and current controls. Notice other versions of
these opto-isolators can be used to isolate the switched outputs also.
The other method of squelch control uses the quieting phenomena during
reception of a signal to open the squelch. When there is not a signal there is
plenty of random noise received, especially high frequency noise. This high
frequency noise is used to close the squelch when the quieting effect is not
present. With this method all that is needed is the three pot connections on
the URC1 in place of the pot that previously controlled the squelch. These
variable pots can also replace the level detection method by tying the wiper
output to the high output.
To use the variable pots:
This is the simplest way of controlling signal levels such as volumes, voltages,
powers, etc. Always tie the common ground of the URC1 to the common on
the unit you are trying to control. If you are worried about the common on the
unit to be controlled not being isolated, run the URC1 off of an isolated power
supply. Using this method should protect the URC1 from damage from
grounding errors. L0 does not have to be tied to common, but must not go
lower in voltage than the common of your URC1.
To use a Level Output as a Variable Power Supply or Voltage Source:
This configuration allows a user to adjust a 12VDC-18VDC unregulated power
supply to a 0-10VDC regulated supply. The regulation in this case is limited to
how well the URC1's regulator is operating. Parts can be modified in value to
URC1 • 17