silicon phototransistor output in a 4-pin dual in-line As per DIN EN/IEC -5, this optocoupler is suitable for “safe electrical insulation” only within .. Y = Manufactured in Thailand. YA = Manufactured in China. XV. The optocoupler is FL C F, should i just join the emittor and collector pins ? . For the triac (pins 4 and 6), with no voltage applied to the LED (pins 1, 2). 3. Signal transmission between circuits of different po- tentials and impedances. □ Applications. DIP 4pin General Purpose. Photocoupler. 1. 4pin DIP package.
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An optocoupler or optoisolatoris a device that contains a light-emitting diode LED and a photosensor photodetector, such as a photoresistor, a photodiode, a phototransistor, …etc. The purpose of an optocoupler is to transfer signals from one circuit to another yet keep them galvanically isolated. Here I want to show you how to check if an optocoupler is working. If you get a value either way or no value at all, then certainly there is a problem with the LED, and you should find another optocoupler.
If the LED is good then we should check the phototransistor, you could measure it with the ohmmeter just like the LED between pins 3 and 4 the emitter and collectorand you should get a high resistance value both ways if the phototransistor is good.
Did you reffer to isolation resistance when you mention some phototransistors have high resistance? I was referring to the junction resistance. If i give the input of V DC what will be the response of this optocoupler…. If the input is at 2V DC, then the output resistance should be around — ohms. For response time or frequency response data, check the datasheet.
Thank you for the information… and i have one more clarifications. I have two circuits. It depends on the 2nd circuit you are supplying the voltage on collector of the optocoupler, optocoupler will never transfer the voltages of circuit1 to circuit2, it decreases resistance between your supplied voltages at collector and emitter on the input of circuit2.
Please correct the pin numbers in image. I use analog ohmmeter with 2 internal batteries, 3V to turn on LED pins 1 and 2and digital V-metar on diode tester mode on transistor side. I like the way you explain things. You helped me understand how to use a tester on a optocoupler Thanks. I was wondering if i could just bypass the optcoupler and see if it works.
The optocoupler is FL C F, should i just join the emittor and collector pins? Any help would be apreciated. I hope it helps. First of all thanks for sharing such an useful information.
measuring a optocoupler
I appriciate… I tried that emprical method for H11B1 optocoupler. But what i want optocoupleg mention is there is a different testing circuit on the datasheet of H11B1. Here is the web site. The question is which one is the right testing method? Emprical method you mention above or the testing circuit on the datasheet of H11B1?
Hi, Both methods are correct. In my example an ohmmeter is connected at the output, in order to see the change in resistance. In the datasheet example, a 10V DC is connected at the output, so that one can check the variation in voltage with a voltmeter or an oscilloscope.
I guess, optoxoupler should work mostly the same as a normal triac. So when current flows through the LED, the triac is triggered and it conducts both ways until the main current drops below a certain level. Better check the datasheet for a test circuit.
Pls let me know.
The LED is basically a diode, and it should not conduct both ways not get values on the meter both ways. Thx and best regards, Geert.
PC817 / EL817 4 PIN Phototransistor Photocoupler
I only have a digital multi meter. How can i test them?
Hi, The MOC, is a phototriac coupler, meaning that instead of the phototransistor, it has a phototriac, which is basically a triac with the gate driven by the LED. For the triac pins 4 opptocoupler 6with no voltage applied to the LED pins 1, 2check with an ohmmeter the resistance opocoupler pins 4 and 6, it should be high open circuit or at least greater than 1 megohm both ways, and this resistance should go down lower than ohms when voltage is applied to the LED, and should remain low even if the voltage is no longer present on the LED.
With no voltage applied to optocouplfr LED pins 1 and 2and with an open base pin 6there should be a high resistance between pins 5 and 4.
PC / EL 4 PIN Phototransistor Photocoupler
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When Firefox stops working, you fire up Chrome. Good design is as little design as possible. The firehose by day and forty beers by night, An engineer may never sleep and still be just as bright. The nice thing about standards is that you have so many to choose from. Step 2 If the LED is good then we should check the phototransistor, you could measure it with the ohmmeter just like the LED between pins 3 and 4 the emitter and collectorand you should get a high resistance value both ways if the phototransistor is good.
Viliam on September 7, at 1: Blumen on October 26, at 7: Michael on January 21, at 3: Muhammad Akhlaq on May 30, at 9: Mihai on July 15, at 8: Mihai on July 16, at 5: Shahid on August 7, at 1: Thank you for the information.
Kannan E on July 19, at 9: Mihai on July 19, at 3: Evis on November 12, at 7: Ado on November 14, at Mihai on February 2, at 5: Hi, First of all thanks for sharing such an useful information. Mihai on March 6, at 2: Arvind Vijaykumar on June 1, at What if optocoypler is photo-Triac instead of Photo-transistor, How to test then? Mihai on June 10, at Sanu sebastian on August 19, at Mihai on August 27, at Sarfaraz on November 8, at 9: Geert Van Droogenbroeck on November 18, at Hi, maybe a stupid question: Mihai on November 20, at 1: Wade on February 5, at 9: Thanks for the easy to follow explanation of how to rest an optocoupler.
Mihai on February 6, optocouplee Nupra on March 18, at 6: Mihai on March 18, at Siroos on October 14, at These information are very good indeed. Sunil on March 3, at 3: Mihai on September 17, at Mohamed on October 9, at 9: How the optocoupler Type SFH acts when the positive line is open. Mihai on October 28, at Leave a Reply Cancel reply Your email address will not be published.