What does optocoupler do in SMPS?
Optocouplers are frequently used in isolated switch-mode power supplies (SMPS) for galvanic separation between the primary and secondary sides as well as from the feedback generator.
How does a optocoupler work in a circuit?
How It Works. A current is first applied to the Optocoupler, which makes the infrared LED emit a light that’s proportional to the current. When the light hits the photosensitive device, it switches on and starts to conduct a current as any ordinary transistor might.
Why would an optocoupler be used in an electronic circuit?
Optocouplers are often used to reject back EMF, noise, and electrical surges from entering an MCU circuit. Optocouplers create a safe connection between high voltage equipment and microcontrollers with a means of complete electrical insulation.
Why do we use two optocouplers in SMPS circuits?
If so , one could be for voltage feedback and one for current feedback from output to the control circuitry. You can draw the circuit of two optocouplers and the other parts just use the block to show them, there is a SMPS circuit with two optocouplers on the end of the article, but it is not the circuit of that product.
What are the parts of simple SMPS circuit?
Main three parts of this simple SMPS circuit are TNY267 tiny switch -II family IC from power integrations. It is enhanced, energy efficient and low power offline switching device. Secondly EE20 core flyback transformer as stepdown transformer which is made up of compact ferrite EE.
How can I interface two TTL circuits using an optocoupler?
This interfacing can be achieved using various special-purpose ‘digital interfacing’ optocoupler devices, or by using standard optocouplers; Figures 14 to 16 show circuits of the latter type. Figure 14 shows how to interface two TTL circuits, using an optocoupler circuit that provides a non-inverting action.
What is an optocoupler?
Basic form and application circuit of a typical optocoupler. Most modern optocoupler devices use a phototransistor as their Rx unit; such a device is known simply as an ‘optocoupler,’ since the input (the LED) and the output (the phototransistor) devices are optically coupled.