Based on the optocoupler TLP181, this breakout board is designed to equip an input optocoupled any circuit that operates at TTL logic level, or to transmit a logical condition between two circuits keeping the two galvanically separated. The optocoupler TLP181 has an infrared LED connected between pins 1 (anode) and 2 (cathode) and an NPN phototransistor connected with the collector to pin 5 and the emitter to 4 (the base is not connected to the outside by pin). By applying a DC voltage at the input (IN), of value between 6 and 30 volts, the collector of the phototransistor output is lead to logic zero (a few hundreds of millivolts) for the duration of the presence of the input voltage. By applying instead a sinusoidal alternating voltage amplitude of between 5 and 30 V, the output will pulse between 5V and logic 0 with a trend that reflects what dell'alternata.

The input LED lights up with the optocoupler currents also rather weak, the order of milliamps and CTR (Current Transfer Ratio) ie the ratio between the output current (in this case is the collector current of the phototransistor ...) and the input current is 60% in saturation and up to 5 times in the best conditions (input current around 5 mA and collector-emitter voltage of 5 volts). As with all breakout board proposals, also in this contact (input, output, power supply) are available on contacts arranged on the sides of the circuit board, is on a row of pitches to 2.54 mm ready to host a pin- strip that allows the insertion of the card on the other. The power breakout board is at 5 volts in continuous and the absorption is very small: 1 milliamps to the maximum; then you can match it to any circuit, also powered by batteries or small solar panels or other solutions for Energy Harvesting.