Brian

5uA Day/Night Circuit

49 posts in this topic

I am posting a day/night circuit for some of you guys that want a low power day night option. This circuit as is will only draw 5 uA total to determine whether it is day or night and give an output on Pin 8 of high when it is night and low when it is day. There is a 1Meg resistor in line with the CDS cell. It can be lowered to adjust the sensitivity but the idle current will go up as you adjust it. I recommend leaving it as is to keep the 5uA idle current. The circuit seems to switch just fine with that setting. I adjusted it and the current went to 200uA in a hurry. Just thought I would mention it.

 

The mosfet is a RFD14N05L.

The chip is a MAX931.

The CDS cell is a PDV-P9005-ND (Digi-Key)

post-4-1113307565_thumb.jpg

Edited by Brian

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I will give it a try looks good. My friends really like the IR cams I have been building and I am looking for a good, low power drawing solution for them to help them get a couple units built. :cool: Thanks for the info.

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Nice! :cheers:

Edited by nendiien

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Nice work as usual Brian :cool: :cheers:

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Thank you soooo much Brian, I have needed one of those for years, for all kinds of things. Now I can finish my video cam, hog light, feeder light... and much, much more. :cheers:

 

Added a label, hope you do not mind.

Edited by 212

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Thanks,

 

Don't mind at all. I assume some times and you know what that gets me.

 

BTW, I did it again. The resistor going to the mosfet should be a 1.5K so the slave charges faster not a 4.7K.

Edited by Brian

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thanks again check me if Iam wrong digi-key # for the compr.931 is

max931cpa-nd $2.46 :cheers:

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I thought I would bump this back up and also say that if you need the output of the op amp to work opposite of the way I have it for high and low then you can swap pin 3 and 4 and it will work.

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I find this stuff fascinating but am truly ignorant when it comes to understanding circuitry and building something from a diagram. Does anyone know of a "dummies" type book they'd recommend? Haven't found a decent one yet and I've been looking for a while. Most seem too extreme as I can't see me etching my own PCBs etc but I'd like to be able to be a little more homebrew capable than I am right now. Any chance of seeing a pic of the above setup?

 

Thanks

 

Krooz

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Krooz... I could not agree with you more!!! I have been doing this for about 3 or 4 years now and I still cannot understand those diagrams or how to put one together.... :blink:

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The only way I know to learn some of this stuff without going to major classes is to start out slow and just dive in to something.

 

Ask questions when you can and go from there. There are some really good electronics guys on the site that come from the old school days that would jump on most of the electronic quetions if you ask.

 

As far as a picture I don't have one and will probably not have the time to make one.

 

I wish I did have. I would post it. I hope to have a board made that all you have to do is put the parts on it but that is a ways out.

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I hope to have a board made that all you have to do is put the parts on it but that is a ways out.

No problem Brian.. That is the biggest question I have is how you get a board and know where to put everything on it.. I have seen the boards sold at radio shack and jameco, but there are all different kinds and was not sure exactly what I was looking at... I will keep checking around and see if I can figure out what to use....

 

:cheers:

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Thanks Brian..... I'm actually toying with the idea of taking a fall course at a local tech college just to have a handle on things. It's probably not as bad as it looks... just foreign to me at this point.

 

Krooz

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Here is a picture of the front and back of this project. The front view board is not complete, as you can see but all the components are on the board. Neither board is connected to the external components but the basic board is done. Hope this helps, it's easy to build.

Edited by Flyguy958

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