An optical isolator is known as a device which enables transmission of an electric signal by making use of the signals induced by light. The theory behind this is that coupling needs to be done between the insulation of input and output of a circuit board or a single wire which makes use of these principles. The basic purpose of any kind of optical isolator or a photo coupler is to make sure that any high changing voltages do not damage the components. This is done via carefully designed and manufactured photo couplers which are sold by a couple of different electronics manufacturers out there. Most known manufacturer of photo couplers is Sharp. If you’re interested in upgrading your circuitry with a device like this, you will need to do some proper researching first. Since this is a component which is intended to protect your devices, it’s important to know exact specifications of the photo coupler you’re looking for. Fortunately, this is no problem since there are plenty of datasheets specific to PC817 photo couplers which you can get for free online and get all the information you need. For starters, you can visit Sharp’s official website where you might find some decent information on how can you order their products, but it’s more important for you to test your circuits first to know what numbers need to be matched and to what extent. Tolerances are very important here and this research will help you save cost on future purchases. You can download the pc817 datasheet here.