MOC81123S Datasheet/PDFOptoisolators - Transistor, Photovoltaic Output
MOC81123S is a commonly used opto-isolator, also known as a photocoupler, with phototransistor output. It uses a number of components to achieve electrical isolation between input and output, and also provides reliable optical transmission of electrical signal. The packages of MOC81123S are available in various styles, such as: both through-hole and surface-mount, DIP 4, SIP 3, SMD 4, and the other combined versions.
Application Field
MOC81123S are widely used in a range of applications. Principally, they are applied for digital logic isolation, several analog signals isolation, or voltage level isolation and protection. Also, due to their high reliability, they are often used in comparatively criticalfields, such as, industrial automation, vending machines, biomass energy management, electric motor control, etc. (Word Count: 393)
Working Principle
At first the light source is turned on by the base voltage, by the core of photodiode is charged and supplies light to the phototransistor. At the same time, the control end of the photoelectric isolation chip will produce a certain voltage, thereby turning on the collector-emitter current of the output phototransistor to drive the output load. This realizes the potential isolation between the control end and the output end of the photoelectric coupling, so as to meet the insulation requirements.
When the voltage on the control side increases to a certain level, the LED inside the MOC81123S chip will be conducted, and the photoelectric coupling will output a pulse signal. The duration of the pulse signal depends on the voltage on the control side, and the voltage on the control side will drop when the pulse signal is output. The control voltage is increased again, and the LED is turned on again, and a new pulse signal is output. This pulsed signal is amplified by an external transistor driving circuit.
Conclusion
In conclusion, MOC81123S is a type of opto-isolator with phototransistor output. It provides excellent insulation performance and high reliability in various fields, such as industrial automation, and electric motor control. Its working principle involves the LED being conducted, and it outputs a pulse signal which is amplified by an external transistor driving circuit.
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