lenzrulz

modified 6 years ago

⭐️Photo relay circuit⭐️

375

06:19:41

A photo relay or light activated relay is a circuit which opens and closes the relay contacts according to the light.

Here a photo diode (LED) is used to sense the light. A potentiometer is used to simulate the photo diode operation.

The photo diode (LED) offers a high resistance when there is no light falling on it.

In this example, the photo diode (LED) is connected in reverse biased condition. The only current flowing through it will be due to the minority carriers.

When light falls on it, the current due to the minority carriers increase and the diode offers a low resistance.As a result the voltage across the diode will not be sufficient to make the transistor Q1 forward biased and the relay will OFF.

When there is darkness the photo diode resistance increases and the voltage across it will become enough to forward bias the transistor Q1 making the relay ON.

The diode D2 is used as a freewheeling diode to protect the transistor from transients produced to the switching of relay. 

By this way the load connected through the relay contacts can be switched ON and OFF according to the light falling on the photo diode.

published 6 years ago

badassfromaus

6 years ago

A photodiode is a PN-junction diode that consumes light energy to produce electric current. What you are talking about is A photoresistor it's an active component that decreases resistance with respect to receiving luminosity on the component's sensitive surface.

giomix

6 years ago

@badassfromaus, in the webpage from come this copied circuit with some wrong changes, there is a photodiode : http://www.circuitstoday.com/photo-relay-circuit. And you are right, description seems about photo resistor. But pay attention, the author wants only enthusiast comments on his post otherwise will report you to admins. So I decide to say that this is a great circuit anyway.

lenzrulz

6 years ago

@badassfromaus, thank you for your comment. What I discovered is that diodes designed for use specially as a photodiode use a PIN junction rather than a p–n junction to increase the speed of response. The wide intrinsic region is in contrast to an ordinary p–n diode. The wide intrinsic region makes the PIN diode an inferior rectifier (one typical function of a diode), but it makes it suitable for attenuators, fast switches, photodetectors, and high voltage power electronics applications. Unfortunately EC doesn’t have photodiodes or photoresistors so the challenge was to use existing components to replicate the circuits functionality and this necessitated some circuit changes. So observationally this circuit may not match the description but the principle should be plausible given the above mentioned component limitations.

lenzrulz

6 years ago

And don’t pay attention to a small number of troublemakers such as @geomix who could have published a corrected circuit for the benefit of the EC community but was unable to do so so he spent his time running around pretending to be helpful by showing my sources and making stupid assertions.

joesoap

6 years ago

Lenz I’ve quietly watched your trolling and bad circuits. I know to look for stars in the description and avoid them

lenzrulz

6 years ago

Likewise @joesoap, the fact that you’ve stopped publishing circuits a long time ago and now resorting to making insidious insinuations reveals your true troublemaking intent. “Birds of a feather flock together” my friend...😎

giomix

6 years ago

Lenz had also copied and pasted his entire response to @badassfeomaus from Wikipedia : https://en.m.wikipedia.org/wiki/PIN_diode. When is talking about of all arguments except for electronic then he use his own words. Sincerely I prefer him when copy paste...

hurz

6 years ago

@giomix, hes a charlatan and has no idea what he is talking about.

kiani

6 years ago

Lenz is a 3 years old with his mumy at the keyboard.

lenzrulz

6 years ago

Screenshot taken and reported to the admins for their perusal, it time to rid EC of troublemakers!

giomix

6 years ago

Here lenz used his own words, for example.

lenzrulz

6 years ago

Published any circuits lately or are you too busy being a troublemaker?

kiani

6 years ago

And here is lenz mumy s words...."I’ve made my argument known along with empirical evidence just as you’ve made your argument known. I respect you Max, we disagree on trivialities and we’re fierce combatants but that element of respect between us has always prevailed. I will honour your request and stop posting comments on this circuit and I hope my opponents will reciprocate my action and likewise respect your wish and cease posting comments about me on this circuit."

lenzrulz

6 years ago

Yep, learn from this example and don’t post your comments on my circuits!

giomix

6 years ago

Lenz, to publish something decent using your own head and not copying by pasting from the web, it commits a time . It's more fast and easy your method, in two minutes you post something, not important if undestood or not by you or wrong or already posted hundred time. I prefer my method, sorry.

lenzrulz

6 years ago

Lead by example, publish a circuit rather than being a troublemaker!

giomix

6 years ago

Who did you think believed that what you wrote was a your own words? Even a child would understand this. To be honest in the life is not a bad thing, do you know?

lenzrulz

6 years ago

No circuit huh? What’s wrong, run out of ideas?

giomix

6 years ago

No, actually run in my life with my family, it's a very good manner to spent the time.

lenzrulz

6 years ago

Too bad you spend so much time writing nonsensical comments and being a troublemaker when you could offer a circuit which corrects the mistakes you claim other circuits have.

giomix

6 years ago

Too much better to be honest in the life! I spend just few seconds to write you something, the same time you spend to post copy-pasted-misunderstood-wrong project.

giomix

6 years ago

The trouble I generated to you is just show to the other users your dishonesty level, copying not only descriptions and projects without write the source but also tech answers to the users ....what you did was not a good figure, I know, you would have preferred that I had not create a trouble to you, like a thief is not happy when policeman catches him...

lenzrulz

6 years ago

I have reported the fact that you only post your stupid opinions on my circuits because you are a troublemaker who isn’t interested in electronics!

kiani

6 years ago

Lenzulz you arr calling over 100 experienced engineers trouble makers.....but it is you and your copy paste strtegy, posing as an expert, and stubborn behaviour, and lack of interest in electronics which is making you a trouble maker...plz. Take the advice of our clinical phsycopathic member and see a councillor..

lenzrulz

6 years ago

How about showing the mysterious list of “100 engineers” and then maybe the EC community will believe the garbage that you spew all over my circuits?

giomix

6 years ago

Your circuits are only garbage themself, so if someone spew other garbage is not possible distinguish the result.

lenzrulz

6 years ago

Publish a circuit my friend...😎

giomix

6 years ago

Would you like a lot uh? But unfortunately for you I'm not interested in publishing, my ego is happy as is, not like your ego happy only if the others believe you are an expert in electronic. So, think to your circuits.

lenzrulz

6 years ago

Bye bye...👋

giomix

6 years ago

Who visit this post will not have any doubt, but only the certainty that you are 100% pure idiot 😅

lenzrulz

6 years ago

Only in your tiny universe my friend...😎

lenzrulz

6 years ago

@Bushmills repeatedly posts fallacious untenable narratives on my circuits accusing me of “spamming”, oh the hypocritical irony. Such pettiness speaks volumes about his assumption that the EC community are so stupid and gullible that they would actually believe his lying narratives!. Report such behaviour to the admins for their perusal. PLEASE NOTE: ** IF @Bushmills FALSE NARRATIVE APPEARS BELOW THIS POST then he has DELETED his PREVIOUS POST and REPOSTED IT AGAIN **

lenzrulz

6 years ago

Narrative reposted

lenzrulz

6 years ago

Narrative reposted

lenzrulz

6 years ago

Narrative reposted

lenzrulz

6 years ago

Narrative reposted

lenzrulz

6 years ago

Narrative reposted

lenzrulz

6 years ago

@Bushmills, any atmospheric toxicity comes from your keyboard as evidenced by your REPOSTED LYING NARRATIVES posted BELOW this comment! *BELOW* - Preposition Beneath, under, lower than, less than, inferior to, subordinate to, subject to, controlled by, under the heel of. That’s right, your lying narratives BELOW - never preceding my comments! Unfortunately, not even your cowardly script usage can help you!

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