![optical isolator definition optical isolator definition](https://ae01.alicdn.com/kf/HTB11zvKXsnrK1RkHFrdq6xCoFXaa.jpg)
The Handic "VIC REL" controller provides protected input and output using 6 relay outputs and 2 optocoupler inputs. An optocoupler (a light-emitting diode (LED) coupled with a photo transistor) can be used to isolate control and controlled circuits. A solid-state relay uses a thyristor, TRIAC or other solid-state switching device, activated by the control signal, to switch the controlled load, instead of a solenoid. This is similar to the circuits used in optical audio compressors.Ī solid state relay or SSR is a solid state electronic component that provides a function similar to an electromechanical relay but does not have any moving components, increasing long-term reliability. The gain of the amplifier is then controllable by the current through the LED. The gain of the amplifier then depends on the light falling on the LDR, which can be provided by an LED (an optocoupler). The third technique, primary-side sensing, can be as accurate as the first and more economical than the second, yet requires a minimum load so that the discharge-event keeps occurring, providing the opportunities to sample the 1:N secondary voltage at the primary winding (during Tdischarge, as per Fig3).Ī crude example is a typical inverting op-amp configuration with a light-dependent resistor (LDR) in the feedback loop. Also, in applications where reliability is critical, optocouplers can be detrimental to the MTBF (Mean Time Between Failure) calculations. The first technique involving an optocoupler has been used to obtain tight voltage and current regulation, whereas the second approach has been developed for cost-sensitive applications where the output does not need to be as tightly controlled, but up to 11 components including the optocoupler could be eliminated from the overall design. Commercially available opto-isolators withstand input-to-output voltages up to 10 kV and voltage transients with speeds up to 10 kV/μs. Opto-isolators prevent high voltages from affecting the system receiving the signal. In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light. Modulation was produced using an optocoupler, a light-dependent resistor whose pulsating signal (producing a lopsided wave) affects the preamp circuit. Later amplifiers, and particularly the Fender Blackface amps of the mid 1960s and the later Silverface amps, used a much more complex circuit, producing the kind of effect that was especially popular with surf musicians. Isolation is provided by the layer of transparent glass or plastic between the LED and detector. Some devices provide up to 60 kHz bandwidth.
![optical isolator definition optical isolator definition](https://image.slidesharecdn.com/transformerandopticalisolation-150509072119-lva1-app6892/95/transformer-and-optical-isolation-5-638.jpg)
The linearity is improved by using a second optocoupler within a feedback loop. An optically-isolated amplifier modulates current through an LED optocoupler.