Inside the Nokero solar light

I have a horrible feeling the video resulted in a lot of sales at a bad time due to the pandemic.

Big Clive

Is anyone else having trouble buying one of these? I ordered one directly from Nokero over 2 months ago. Paid for it and the shipping. No light and no response to my repeated email inquiries.

The solar panel charges the lithium cell directly when its MOSFET transistor is on. It seems to rely on the current limiting of the cell rating at peak sunlight. Not sure what that actually is due to lack of sunshine to test it with.

Big Clive

Guessing here but voltage starts at 5v from panel, voltage drops from 1K resistor and the diode in the chip brings the voltage to about 3.2v under the current we are talking here, 3.2v is perfect for LifePO4, the tiny current flow could be used to power the microcontroller from the panel while the battery would essentially not be charged and even if it is it can handle far above without any issue. Thoughts?

I would order one of these for funsies and to support the cause, but only if it only used for avoiding homework and playing with electronics and gadgets instead so some real learning happens.

Michael Thompson

Very nice. A great light, and a great cause. I just bought three. One for me and donated two. Thanks Clive!!

Chuck Kirchner

Clive, just saw this was shared and commented on by Paddy McGuiness on Twitter - https://twitter.com/gemini92688663/status/1354735904066314242?s=21

Lyall Moffitt

Clever stuff. TBH once you've got a processor in there you might as well make use of it.

Mike Page

The solar panel is soldered. But you've just made me realise what the transistor is for. It's acting as a microcontroller controlled rectifier so there's no diode loss from a traditional solar charge circuit. I've just tested it, and the microcontroller only switches the transistor on when the solar cell voltage exceeds the lithium cell voltage. That way the solar cell won't leak battery current at night.

Big Clive

LiFePO4 batteries are used in a lot of industrial equipment. But just haven't taken off in home stuff yet. The charge voltage difference is an issue for loose cells.

Big Clive

No it doesn't.

Big Clive

It's controlled by the software.

Big Clive

Could the 1K be solar panel reverse protection? It's on a connector, right?

Mike Page

I expect paraffin lamps are perfectly fine. They did us as a family when camping in the 70s. They chuck out a lot of light! But innovation is good and free stuff is double good so this seems OK. I'd heard about something similar a few years ago, mate of mine asked will it work? I said make sure the solar cells are BIG. (Are they BIG? I like 'em BIG! - Prof Peach) Clive - I understand how the use of "Homework == Good" as marketing material would touch a nerve (Arbeit Macht Frei was hardly a good slogan, either). But other cultures have other priorities - and in countries where education is NOT free, it is highly valued. And any value the kid can add without paying is seen as double good. YMMV - as always.

Mike Page

Did it work?

Mike Page

A really interesting circuit, and that battery - why isn't it more widely used? It seems to be very efficient.

Mike Hughes

does the lifepo4 battery have a charge protection circuit under that blue wrapping?

Ruthsarian

Make sure your counsellor doesn't give you homework.

Ymir the Frost Giant

3 hours homework per night, and that included Saturdays. Public schools for you!

Andrew Donaldson

Very neat. Nice to see something that has been well thought out.

Jeremy Travis

Looks like I might be in a minority for actually enjoying doing homework when I was a kid then. A great excuse to stop my Mum from turfing me out of my room!

Jon Knight

Wow, I think I owe my former students an apology and will make an appointment for some in dept counseling ;)

Hub Rijcks

Could the transistor in the charge circuit be there solely if the software in the chip did crash?

Lostngone

Thank you for the feedback Clive, I always see or learn something new every video. And thank you for sharing your knowledge and experience with electronics!

Cleveland Prescott

It doesn't fit. Different thread.

Big Clive

The MOSFET always has its source referenced to the processor negative, so I don't think it's for that. I'm not sure why they chose 1K. Nor why they also used a separate 1K resistor with a different naming system so they had to have two tubes iof different 1K resistors on the pick and place machine.

Big Clive

I think the 1k resistor could also be used if there is a problem like the LED going open , it could turn off the mosfet below the solar cell because it would have lost its way to use the LED to shunt the load. Do you think my amateur educated guess might have any merit and/or my guess in my previous have any merit? Thanks in advance for the videos and learning enough to make a guess to it's function.

Cleveland Prescott

I just never did my homework. Also when asked to go to Sunday school by the CoE school I went to as a primary school, I promptly became, and remain, an athiest. I think there is a recurring theme in there somewhere....

I have a question, Clive. Both the Nokero and the Knokero have an Edison screw type shape in the plastic molding. Will it actually screw into an ES fixture in your roof in please of a bulb?

Loscha

I think the 1k resistor is so the micro can turn on the mosfet below the 1k resistor so it can be access to the negative rail in case the battery protection cuts off the power from the battery so the micro can power itself from the solar cell. Just my amateur guess. As a guess do you think iam on to something?

Cleveland Prescott

I never did my homework. I always felt the same.

Michael Thompson

You can use it to scrutinise toilet bowls with harvested solar energy.

Big Clive

What's this have to do with plumbing systems?

Jason Brinkerhoff