Chinese toys

[kt315]

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

[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.

[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.

[kt315]

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

[dbanner]

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

[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?

[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.

[homefire]

LOL, Even Amazon is doing that now.

[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.

[kt315]

received second frequency meter kit. my mod on schematic.

[kt315]

sure working chip -!
https://www.aliexpress.com/item/3301...3da24c4dpkMEvQ

[homefire]

What kit is this ?

[kt315]

HF in kit they always put unfake chip LOL!

https://www.aliexpress.com/item/3296...27424c4djJW4Nn

[kt315]

anybody did this amplifier? i solder the board now. https://www.aliexpress.com/item/1000...27424c4duzufAJ

product details:

Audio power amplifier driver LME49810 is the highest power density amplifier driver. The single-chip drive built compensatory clamp circuit can be minimized distortion audio system .LME49810 chip can drive high-power discrete transistors, optimized for output power up to 3000W high-end consumer electronics and professional audio equipment audio system. the total harmonic distortion and noise can be reduced to 0.0007% .LME49810 chip built-in high-quality, high-performance power amplifier output stage driver required audio circuitry, can replace more pieces of discrete components.

1.6mm thick sheet using double-sided PCB, 2.0 oz copper thickness, HASL whole process to ensure the size of the current through the good performance. PCB-class quality.

Basic parameters:

Voltage: + - 45V (DC) and + -60V (DC)

Size: 255MM * 78MM

[Andi68]

I had a similar tester, and after almost a year, it has passed