Fake solar-powered calculators? - Page 1
Forum section: electronics / beginners

author: edy
author_rank: Super Contributor
timestamp: July 25, 2014, 04:34:48 am
content: Hi folks,I recently opened up an old "binder" calculator like those shown below (attached) so I could scavenge some parts. Not much in there but to my shock the "solar cell" was fake, not attached to the circuit at all, it looked like a piece of flexible plastic made to look like a solar cell. The calculator was powered by a battery, there is no way a panel that small could have charged up that battery, even it was connected and real.Has anyone else seen this? Why put a fake solar cell not connected to anything? I wonder how many people were duped or since it is usually sold in a bundle with a cheap binder, nobody cares.

author: edy
author_rank: Super Contributor
timestamp: July 25, 2014, 04:38:48 am
content: I just did a Google search... apparently it is quite common. I never knew...Here is just one of many reports... You live you learn!http://johnfixesstuff.blogspot.ca/2012/10/how-repair-solar-calculator.html?m=1

author: Stebanoid
author_rank: Contributor
timestamp: July 25, 2014, 05:53:54 am
content: It's common in cheap calculators. Have seen this a lot.

author: AndyC_772
author_rank: Super Contributor
timestamp: July 25, 2014, 06:43:12 am
content: A Ducati with electrical problems? Who'd have thought it...

author: Richard Head
author_rank: Frequent Contributor
timestamp: July 25, 2014, 09:10:49 am
content: A Ducati with electrical problems? Who'd have thought it...Never a truer word spoken.

author: amyk
author_rank: Super Contributor
timestamp: July 25, 2014, 11:57:05 am
content: These calculators are so cheap that apparently a solar cell is 10% of the cost.It is a dummy solar, the additional cost of real solar is USD 0.05 / pc. It's a feature:fake solar panel for decorated

author: wraper
author_rank: Unknown
timestamp: July 25, 2014, 12:29:28 pm
content: Quote from: edy on July 25, 2014, 04:34:48 amSize is big enough as current needed is very tiny. Calculators with real solar cell have approximately the same size. Actually real solar cell usually is easily distinguishable just by look of it. It is always absolutely flat and look more like glass rather than plastic, have more mirror like look. Also if segments of that solar cell are not equal of like half cut on the sides it is a clear sign of the fake. You can also just poke on it from the outside, if it is flexible then it is a fake.

author: edy
author_rank: Super Contributor
timestamp: July 25, 2014, 01:23:01 pm
content: It just seems very unethical and a ridiculous practice to do that. I'm starting to wonder what other "fake" stuff is out there.I remember back in the days of Ghetto blaster radios, they would add on rows and rows of graphic equalizers that I am sure did nothing as I could not hear any difference at all! Anyone else notice that?

author: jmoreland79
author_rank: Regular Contributor
timestamp: July 25, 2014, 04:39:43 pm
content: It's not really meant to deceive anyone necessarily, giving the benefit of the doubt.It's likely just a Chinese knockoff of something. Someone says here: build a calculator like this. So they copy the aesthetic design EXACTLY and just do whatever to make the innards work.This is why Chinese knockoffs are called...knockoffs. Designs are copied without properly reverse engineering them so critical components or characteristics are left off if the person doing the design can't figure out what components are meant to do.

author: Rick Law
author_rank: Super Contributor
timestamp: July 25, 2014, 06:57:01 pm
content: Do they have a label that it is solar powered? If not, it is probably it is a generic shell that they can source cheap rather than fake.Also, not all solar calculator "charge a battery". My kid uses a (not so cheap) TI calculator. I had to open it up just the last 3 or 4 days for repair after it was stepped on and failed. The solar cell is real and connected, but the calculator does not use a rechargeable. It has a clipped on 2520 non-rechargeable Lithium battery and no accommodation was made to replace the battery once drained. Unless you are comfortable enough to disassemble the calculator into pieces and reassemble it after battery replacement, otherwise for all practical purpose, it is a non-replaceable battery.Given the set up I saw in there include how low the battery drained in 1 year (and used only 3 during tests), I would think it was battery powered at least 50%.That one, I consider it disingenuous at best. I think the solar panel there is just to justify the lack of an accessible battery replacement method rather than to really serve as the primary power source.

author: Zbig
author_rank: Frequent Contributor
timestamp: July 25, 2014, 07:01:19 pm
content: Quote from: edy on July 25, 2014, 01:23:01 pm

author: SeanB
author_rank: Super Contributor
timestamp: July 25, 2014, 07:09:49 pm
content: I have seen many with a real amorphous panel in there, and as well the small button cell, which is actually charged by the solar panel. It is reasonably safe as the panel will only deliver about 100uA into a short circuit in direct sunlight at noon, so the coin cell is very unlikely to be overcharged unless you leave the calculator out in sunlight all day. There is a small germanium diode to prevent the cell discharging back through the panel.The solar cell does provide a useful extension to cell life, you can see that the display will fade as the cell ages and placing it in direct sun for a half hour brings it back a lot. As they use a common LR43 cell in many cases or a 377 cell replacement is easy, once you undo the dozen or so small screws holding the unit together. I have done quite a few Sharp branded ones that are used at work.

author: Rick Law
author_rank: Super Contributor
timestamp: July 25, 2014, 07:46:31 pm
content: Quote from: Zbig on July 25, 2014, 07:01:19 pmI do draw a distinction between those who actually claimed solar power vs those who doesn't but instead just use a case that has the capability.Unless they claim such capability, one should not consider it fake. I had (in the past) a $5000 plus hp managed switch that has empty but covered slot for Gigabit optical (when optical was the only way to get to 1GB). The switch was not advertised as optical-capable. It merely shares the same case (but not model number) of another model.Quote from: SeanB on July 25, 2014, 07:09:49 pmI agree, the power LCD calculator need is so small. Even with the example you shown, a well designed calculator has battery that lasts almost forever. My HP16C from the 1980's are still on its original battery and I use it at least twice a week (bill payment cycles, always double check my mental-math with the calculator). A better battery is probably a better solution.The energy use in manufacturing, transporting, and installing these baby-panels probably exceeded their energy contribution by many folds... I can't think of a manufacturing process that can moving a 1/2gm panel into the plastic shell,solder it, and test it and that the process would consume less that a milli-Watt-hours (1W equipment ran for 0.3 seconds). Say there is one, it would still be just one part. Forklift loading, tracking, and shipping of them every node...In truth, I really doubt if they add any meaningful power for the cost to the environment they incur. Ifthesethere is one way to introduce a cleaner environment, this is one of them. There is no need to introduce more toxins into the environment by making these solar cell panels and more cost to the environment in transporting them around.Rick(EDIT-typo (strike-out font) corrected

author: DRT
author_rank: Regular Contributor
timestamp: July 25, 2014, 07:58:43 pm
content: I saw something similar in a 'solar-charged' torch I picked up for peanuts in Hong Kong. The bizarre thing was that the solar cell was real, but unconnected. The battery was a primary lithium cell. The PCB looked like it could have been configured to be the genuine item.