Abstract: A transmitter for driving a perimeter wire of an animal control system, in which a collar is attached to an animal, and the collar has a signal receiver configured to receive signals outputted to the perimeter wire by the transmitter. The collar is adapted to trigger a control stimulus responsive to detecting a pre-determined signal pattern received at the signal receiver. Different collars have different pre-determined signal patterns. The transmitter has a user interface allowing the transmitter to be configured to output the pre-determined signal pattern for a particular collar. In one aspect, the transmitter monitors current in the wire and adjusts signal magnitude driving the wire and achieves more consistent stimulus activation and detects system abnormalities. Data defining patterns for the different signal types can be stored in a database and be assembled into an appropriate pattern for a particular collar by a microprocessor.