Optocoupler Isolation Circuits for Industrial Application

Optocuploare în Aplicaţii Industriale

Down-link isolation takes a single optocoupler to pass a standard digital signal

Detecting the presence of the mains voltage requires ground isolation

Standard LED transmitter in optocouplers cuts half wave of the AC mains-voltage, i.e. optocoupler also rectifies the input voltage

Controlling both pulses of the mains

Low Current Sensing

By-passing the sensor with the optocoupler transmitter

allows higher current sensing

Same function for AC voltage detection

Threshold Detector plus Isolated Switch

Overvoltages in mains voltage are common

Voltage Surge

Damped Sinusoidal Voltage Spike is Typical

Current Dividing Allows Level Adjustment

Filtering capacitor smooths possible voltage spikes

Non-dissipative voltage divider saves power

Bi-polar voltage clamp uses dedicated components