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Change timing period to gadget ?

Externet

Aug 24, 2009
854
Joined
Aug 24, 2009
Messages
854
Hello.
My poor vision cannot reverse engineer now this $1 non-contact AC detector probe from Aliexpress.
----> https://www.aliexpress.com/item/3256804179002546.html?spm=a2g0o.productlist.0.0.b7a676aaPvFuj1&algo_pvid=333a1c52-53be-40e8-a0fc-24db71ce29a8&algo_exp_id=333a1c52-53be-40e8-a0fc-24db71ce29a8-22&pdp_ext_f={"sku_id":"12000028920452873"}&[email protected][email protected]!12000028920452873!sea

It beeps like at 2Hz, would like to modify to 1 beep/chime every 60 seconds. Inside there is a 74HC14, a DC buzzer, bunch of dividing? resistors and 2 AAA cells; cannot follow tiny traces to make its schematic :-( Any help will be appreciated.

It works like the video in here if you want to see it ----> https://www.amazon.com/Mr-Electrica...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

(Ignore its flashlight feature)
 
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Martaine2005

May 12, 2015
4,402
Joined
May 12, 2015
Messages
4,402
Hiya,
Look up bigClive on YouTube, he did a few videos and reverse engineered several of these non contact pen types.
I just looked and found one but it wasn’t your type. Go through his videos and have a look. He definitely has a couple of vids.


Martin
 

John Canon

Jun 1, 2022
81
Joined
Jun 1, 2022
Messages
81
The beeper sounds so happy. Why do you want to make it sound sad ?
California Raisins.jpg
 

CircutScoper

Mar 29, 2022
300
Joined
Mar 29, 2022
Messages
300
Hello.
My poor vision cannot reverse engineer now this $1 non-contact AC detector probe from Aliexpress.
----> https://www.aliexpress.com/item/3256804179002546.html?spm=a2g0o.productlist.0.0.b7a676aaPvFuj1&algo_pvid=333a1c52-53be-40e8-a0fc-24db71ce29a8&algo_exp_id=333a1c52-53be-40e8-a0fc-24db71ce29a8-22&pdp_ext_f={"sku_id":"12000028920452873"}&[email protected][email protected]!12000028920452873!sea

It beeps like at 2Hz, would like to modify to 1 beep/chime every 60 seconds. Inside there is a 74HC14, a DC buzzer, bunch of dividing? resistors and 2 AAA cells; cannot follow tiny traces to make its schematic :-( Any help will be appreciated.

It works like the video in here if you want to see it ----> https://www.amazon.com/Mr-Electrica...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

(Ignore its flashlight feature)

Well, you could take the "shotgun" approach and, since the beeping period is probably controlled by an RC timeconstant, increase all the capacitances by a factor of 120.
 

Externet

Aug 24, 2009
854
Joined
Aug 24, 2009
Messages
854
Thanks, fellows.
Found the exact item with the 74HC14 somewhere else, but still no schematic to attempt modify it properly.
---->


Found a schematic that claims done with a 4017 instead. It does not matter which chip, I could build it with such instead, am after only the 1 chirp per minute. How to modify still do not see it.AC sensor.png
 
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