Chinese toys

[kt315]

received XR2206CP, this is 5th i bought. amazingly this is again F0919 series. was angry. put it in gen board for checking.
working! looked more atttentionally and saw tiny difference. must do pics.

[homefire]

LOL, Even Amazon is doing that now.

[Qiaozhi]

Dear Anatloy Dirtymad,
People have asked product questions that you may be able to answer.Can you help them by sharing your product knowledge?

Haha!
They're not the only company getting customers to answer other customer's questions. Tripadvisor do that all the time.
Just ignore it.

[kt315]

banggood asking me to help people. my therminology in english is bad. i ask your help to sort out in that.

Dear Anatloy Dirtymad,
People have asked product questions that you may be able to answer.Can you help them by sharing your product knowledge?

https://www.banggood.com/Electronic-...p-1035473.html

Q: Hi there, i need to find distances between spacers and case screw holes located at the inner bottom of the enclosure. Is there a datasheet for this product?

---
what he meant?

[dbanner]

Seems they are second hand. New old stock or second hand? Not sure what's the deal there.

[kt315]

interesting those opamps are original? https://www.aliexpress.com/item/3305...chweb201603_55

[Altra]

Well here is what they use to do back in the day. Again, the ubiquitous 555. .

Unfortunately I come from "back in the day" and remember when the 555 was new. Google search for Walter Jung's "IC Timer Cookbook" he also wrote an Op-amp cookbook which I still reference. In addition he did a write up for Analog Devices. Don Lancaster's Filter Cookbook and CMOS Cookbook. are still on the shelf.

[dbanner]

Got one of these for fun. It actually works well but would need a buffer amplifier on the output to test anything other than logic.

https://www.ebay.com/itm/Adjustable-...52f4d97cb4a7f0

This module looks very good.
Well here is what they use to do back in the day. Again, the ubiquitous 555. This circuit can be adjusted from 1% to 99% duty cycle. Frequency at 1.2Khz. Seems good basis for a simple pulse machine TX.

[kt315]

it is square wave output so you need just a clue. one transistor.

[Altra]

Got one of these for fun. It actually works well but would need a buffer amplifier on the output to test anything other than logic.

https://www.ebay.com/itm/Adjustable-...52f4d97cb4a7f0

[kt315]

DB
your project is sure nice. thanks lots. but novaday those chinese chips are not recommended working above 12V (+-8V on your schematic ie 16V).
while original can work with 24V max, according datasheet.

[kt315]

gave five-star and later wrote:

Monolithic function generator integrated circuit tested now, no signal output.

https://www.aliexpress.com/item/3295...chweb201603_55

[dbanner]

The Analog Discovery 2, I believe has function generator and good software interface. It can do sweep functions as well as step functions etc.
Must be extremely useful in design and testing circuits. Has oscilloscope function of course, and can do spectrum analysis. This device seems well worth the investment. Keeping up with the times and all....?

[dbanner]

Found this old project for a Function Generator using Exar's famous but now obsolete 2206. This one looks to be a really good design.
It's a far cry from that bare bones circuit from ebay.

[kt315]

and again i get fake chip. he sends 0919 series chip instead 0918 showed on his pic.

https://www.ebay.com/itm/1PCS-Exar-X...e7f3%7Ciid%3A1