Counterfeit Dallas DS18B20

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tronde
Posts: 587
Joined: Thu Jan 18, 2018 11:08 am

Counterfeit Dallas DS18B20

Post by tronde » Thu Jan 18, 2018 11:08 am

I know some of you are playing whit these sensors. They are sold cheaply on ebay, but I think there is a reason for that...

The original manufacturer, Maxim Intergrated, indicates a budgetary price of $1.88 @1k so no real surprice I got what appears to be a mix of NPN-transistors and thyristors when I paid less than USD 8 for 10 pcs.

They are all marked as DALLAS DS18B20 with the same batch numbers. Funny thing is that there are some minor differences in the casing indicating they are not made on the same assembly line.


I suggest you don't buy form this seller (beautyzz2009).

http://www.ebay.com/itm/1-10Pcs-DS18B20 ... 1938845675


I have filed a complaint with ebay.

etompau
Posts: 2291
Joined: Thu Jan 18, 2018 11:08 am
Location: Skåne

Re: Counterfeit Dallas DS18B20

Post by etompau » Thu Jan 18, 2018 11:08 am

This is the downside of ordering small electronic parts from the other side of the world, it's very easy for the seller to send whatever he/she likes.
The good side is that you normally you can get a refund from Ebay, and that the sellers seem to be very carefully not to get involved with complains from Ebay,/customers as this in the end can close his business.

For me, the low prices makes it worthwhile to order electronic parts, even if there is a small risk of receiving fake parts or have to wait 1,5 months.

tronde
Posts: 587
Joined: Thu Jan 18, 2018 11:08 am

Re: Counterfeit Dallas DS18B20

Post by tronde » Thu Jan 18, 2018 11:08 am

"Dear customer, We are deeply sorry for this inconvenience. Every product that we ship is totally new and fits the product description."

Maybe, or maybe not...
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etompau
Posts: 2291
Joined: Thu Jan 18, 2018 11:08 am
Location: Skåne

Re: Counterfeit Dallas DS18B20

Post by etompau » Thu Jan 18, 2018 11:08 am

Tronde, thanks for this info, it seems that I also have received fake DS18B20 sensors. Ordered 5 sensors, non is working, and they have exactly the same marking as yours.
Awaiting comments from the seller (not the same seller as you had).

tronde
Posts: 587
Joined: Thu Jan 18, 2018 11:08 am

Re: Counterfeit Dallas DS18B20

Post by tronde » Thu Jan 18, 2018 11:08 am

The chinese are some kind of cute :?

"Dear buyer, Sorry for your any trouble, as the postage for you to send the item back will be very high,could you agree that we refund a half money to you? And you can keep the item,is that OK? "

I said NO, thank you in a polite way.

"The seller accepted your return of 1-10Pcs DS18B20 TO-92 Temperature Sensor Dallas Thermometer Temperature Sensor, and refunded you AU $10.19. It should be available in your PayPal account.

You don't need to return this item to the seller - you can keep the item."


At least ebay's money back garantee is working.


Which seller did you buy from?

etompau
Posts: 2291
Joined: Thu Jan 18, 2018 11:08 am
Location: Skåne

Re: Counterfeit Dallas DS18B20

Post by etompau » Thu Jan 18, 2018 11:08 am

My guess is that the sellers also have been fooled by a fake lot of DS18B20. By selling fake products they are putting their reputation on stake, and in the end, risking the closing of their Ebay business.

http://www.ebay.com/itm/181846732581?_t ... EBIDX%3AIT

tronde
Posts: 587
Joined: Thu Jan 18, 2018 11:08 am

Re: Counterfeit Dallas DS18B20

Post by tronde » Thu Jan 18, 2018 11:08 am

etompau wrote:My guess is that the sellers also have been fooled by a fake lot of DS18B20. By selling fake products they are putting their reputation on stake, and in the end, risking the closing of their Ebay business.

http://www.ebay.com/itm/181846732581?_t ... EBIDX%3AIT
I'm awaiting some voltage regulators from them. The price was realistic, so I hope the best.

I did not try to sort out the DS18B20's with the seller. I filed a complaint directly to ebay because they was obviously fake and non-functioning. I have read about fake and poor functioning DS18B20's as well.

tronde
Posts: 587
Joined: Thu Jan 18, 2018 11:08 am

Re: Counterfeit Dallas DS18B20

Post by tronde » Thu Jan 18, 2018 11:08 am

Some reading about China and counterfeit and recycled electronics parts.

http://rube.asq.org/asd/2009/03/complia ... -parts.pdf

etompau
Posts: 2291
Joined: Thu Jan 18, 2018 11:08 am
Location: Skåne

Re: Counterfeit Dallas DS18B20

Post by etompau » Thu Jan 18, 2018 11:08 am

Not a very nice picture of the Chines backyard re-cycling industry. I guess it must be hard for serious manufactures of electronic system/parts to avoid fake products.

krambriw
Posts: 654
Joined: Thu Jan 18, 2018 11:08 am

Re: Counterfeit Dallas DS18B20

Post by krambriw » Thu Jan 18, 2018 11:08 am

Thank you, unbelievable what they are up to ! This not really what we in west define as recycling...

Best regards, Walter

tronde
Posts: 587
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Re: Counterfeit Dallas DS18B20

Post by tronde » Tue Oct 23, 2018 9:47 pm

I bought 10 DS18B20 from Banggood.

I can't prove they are fake, but they don't behave like any of the 14 other DS18B20 I have, two different batches of 7 each.

When I test them, it is impossible to have more than three of them connected to the same bus. I can have all of the other 14 I have one the same bus, and I can have 3 of the ones I got from Banggood in addition. Regardless of how I connect them, I can not have more than 3 of them connected at the same time. Only 3 (no other DS18B20's) is OK, 4 or more does not work. None of the DS18B20 on the bus is recognized if I have more than 3 of this batch.

I bought 10 items. Five are well within the tolerances, five are outside. All items respond as expected to 9, 10, 11 and 12 bit resoulution settings, and they remember the setting when powered off.

Has anyone experienced something like this?
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