DIY: Let there be LDRs! The Photo-Resistor Intro.1/2
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- Опубликовано: 28 авг 2024
- The light or the absence of it can control a 120V load!
You just have to put together three modules, like in the video.
Today is the stage one, the LDR amplifier.
Cheapest light sensor on the market? The LDR - Light Dependent Resistor
And what operational amplifier are you using in the diagram? The µA 741?
For a simple task like this one, impossible to find a cheaper one.
Still manufactured 66 years later. Imagine…
It compares the variation of the voltage between the LDR and the potentiometer on one side, vs. the half power supply voltage on the other side of the bridge. The LDR sees the light? The op-amp output is high.
The LDR goes dark? The op-amp output goes low, triggers the PNP transistor and your Load goes ON!
Link to the signal amplifier diagram: drive.google.c...
Enjoy the light controlling the noise and thanks for watching!
CU soon.
Great detailed explanation for LDR
@zakizaki1197 Thank you Zaki. Always a pleasure to hear from you
Prática a tua explicação, porém, fiquei ainda com uma dúvida: Desculpe-me a ignorância, mas a segunda configuração funcionará como luminária automática noturna? Saudações do Brasil 🇧🇷
Qual o valor do resistor que vai ao led?
@luizfernandolessa1889: This was only the first stage of the project, showing how to connect a LDR to an amplifier. The next two stages are presented in my Saturday's last video. Yes, the project can automatically control a load, 12V DC or 127/220V AC, if you use a kind of relay box like the one I presented in my video "ruclips.net/video/DzwkuKSlfwo/видео.html"
In the video description you have the link to download the full project diagram.
Thanks a lot for your feedback and interest.
CU
@@luizfernandolessa1889 The resistor size is 1Kohm. Cheers.
If you have other questions, don't hesitate