Before revision: Resistive opto-isolator (RO), also called photoresistive opto-isolator, vactrol (after a genericized trademark introduced by Vactec, Inc. in the 1960s), analog opto-isolatorIn PerkinElmer literature.
After revision: Opto-isolator VTL2C1 with LED input and photoresistor outputResistive opto-isolator (RO), also called photoresistive opto-isolator, vactrol (after a genericized trademark introduced by Vactec, Inc. in the 1960s), analog opto-isolatorIn PerkinElmer literature.