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What are the two types of optocoupler that are mainly use for DC circuits?
Optocoupler Types The photo-transistor and photo-darlington devices are mainly for use in DC circuits while the photo-SCR and photo-triac allow AC powered circuits to be controlled.
How a relay works in a circuit?
Relays control one electrical circuit by opening and closing contacts in another circuit. When a relay contact is Normally Closed (NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to the contacts will change their state.
How does a relay work in an optocoupler?
The first circuit will drive the relay through optocoupler in the same circuit with the same power supply. Whereas the second circuit is completely isolated from the trigger source. The relay is powered with a separate circuit or power source. 1. 2. 3. 4. 5. 6. 7. The working of both the circuits is simple, they are using only a few components.
Why are optocouplers referred to as opto isolators?
The diagram above shows the pinout diagram of the typical optocoupler in DIP package. The device is also known as opto-isolator since no current is involved between the two chips, rather only light signals, and also because the IR emitter and IR detector feature a 100% electrically insulation and isolation.
How is optocoupler used in DC based switching?
In the upper image the internal construction or the TRIAC based opto-coupler is shown. TRIAC is mainly used where AC based control or switching is needed. The led can be controlled using DC, and the TRIAC used to control AC. Opto-coupler provide excellent isolation in this case too.
What kind of voltage does optocoupler pc817 use?
The working of both the circuits is simple, they are using only a few components. They can operate at a wide supply voltage ranging from 3.6V to 12V DC. Optocoupler PC817 used here has an LED and a phototransistor in it. So when this circuit is powered the LED will receive the voltage and light up.