The power supply module converts a quasi-square wave, 50 – 60 Hz AC input voltage into four well-regulated DC output voltages. This reduces service outages by converting long duration AC surges. An optocoupler (or opto-isolator) is a component that transfer signals between circuits using light. In this guide, you'll learn how they work and how you can use one in your own projects. Optocouplers are very useful when you need to isolate different sections of a circuit, for example in power. Optocouplers become specifically useful where an electrical signal is required to be sent across two circuit stages, but with an extreme degree of electrical isolation across the stages. Unlike transformers or capacitors, which can only transfer AC signals across the isolation barrier, optocouplers can. The Schmitt inverter at the output performs several functions; it ensures that the output conforms to HCT voltage and current specifications, it also provides very fast rise and fall times for the output, and corrects the signal inversion caused by the phototransistor being operated in common. The working principle of optical modules is illustrated in the diagram shown in the Optical Module Working Principle Diagram. The transmitting interface inputs electrical signals of a certain bit rate, which are then processed by internal driver chips. The forward amplification path in the RF amplifier module is composed.