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Originally Posted by Dinush
On the controller, it says that the Digital I/O ports have a grnd a +5V I/O. However, the output on the line sensor outputs at 12 V. Will it be okay to connect the white wire directly to the digital in? Has anyone actually done that?
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All,
This is one of those confusing issues in electronics. The sensors reguire 12 volts but the output is not 12 volts. The output circuitry is actually two transistors whose collectors are the output pins. They require a pullup to a voltage from the device they are feeding. In this case the pullup is built into the RC and "pulls up" to 5 volts, the RC power supply. The two outpus are electronically opposite of each other such that one is "on" when the other is "off". When an output is "on" the transistor conducts to ground and so acts like a relay or switch closing a circuit to ground. When connected to the RC current flows from the RC power supply through an internal resistor to the output lead of the sensor and then to ground. The internal resistor limits the current drawn from the internal power supply.