Patent ID: 8570770

Claim:
An opto-isolator multi-voltage detection circuit comprising: a voltage input, the voltage input arranged for connection to the voltage source; an opto-isolator having a light-emitting diode (LED), the opto-isolator configured to detect the presence of an input voltage applied to the voltage input from the voltage source; a diode, the diode arranged for connection to the voltage input; a first transistor having a gate, a source, and a drain, the drain of the first transistor operatively coupled to the diode, and the source of the first transistor operatively coupled to the opto-isolator; the opto-isolator, the diode, and the first transistor arranged such that a current flowing forward from the diode biases the LED, and further such that any power dissipated through the first transistor in response to the input voltage and to the current is maintained at or below an acceptable level for operation of the first transistor; and a DC to DC converter operatively coupled to the source of the first transistor and the opto-isolator, the DC to DC converter configured to maintain the current from the diode.