An optocoupler, also known as an opto-isolator, photocoupler, or optical isolator, is a type of electronic component that uses light to transfer electrical signals between two isolated circuits. Optocouplers prevent high voltages from harming the system receiving the signal. Commercially available optocouplers can withstand input-to-output voltages as high as 10 kV as well as voltage transients with speeds up to 25 kV per microsecond. The most common type of optocouplers feature an LED and phototransistor in the same housing. Other types include LED-photodiodes, LED-LASCR, and lamp-photoresistor packages. Opto-isolators typically transfer digital on/off signals, though some techniques allow them to be used with analog signals. Read more >>