Unexpectedly complex ceramic PCB (I broke it!)
Added 2023-06-26 03:56:32 +0000 UTCThis is a non contact voltage detector pen that I bought a VERY long time ago. Probably when they first appeared. It was subsequently banned by the safety crowd for the perceived risk of it having a metal body.
The circuit board inside is unusually complex and expensive looking.
https://www.youtube.com/watch?v=U6vrFSSAPmg
Comments
I've learned from you, Clive. That's why I'm here. Cheers!
Mike Page
2023-06-27 14:43:50 +0000 UTCIt reminded me of that too.
Big Clive
2023-06-27 05:47:39 +0000 UTCKnowing your design history I do sometimes wonder if I'm looking at one of your designs.
Big Clive
2023-06-27 05:42:01 +0000 UTCI did not design the battery cover ;)
Mike Page
2023-06-26 21:23:30 +0000 UTCThe Kewtech Kewstick Duo is a good, audio visual, and fairly inexpensive NCV tester.
Gadgetman
2023-06-26 16:42:13 +0000 UTCThere are a problems using a logic gate. The main one is that sensitivity will vary with battery voltage. Even with Schmitt trigger inputs. Secondly there's a frequency dependence because the probe capacitance forms a differentiator.
Mike Page
2023-06-26 12:31:47 +0000 UTCA metal body might be fine with a finger barrier. But there's absolutely no need because battery capacitance easily swamps out probe capacitance.
Mike Page
2023-06-26 12:15:39 +0000 UTCI worked at Mullard Research in the late 1970's and the consensus at the time was that the future was going to be in ceramic circuit boards with screen printed components. I worked on improving and developing the stainless steel screens and conductive inks. The technology was not quite the revolution that was hoped for. It was a success, but not the game changer that was expected.
Dave Davies
2023-06-26 05:22:29 +0000 UTCThe second Darlington design always reminds me of your Ghost Detector https://youtu.be/oA5cuLMHIsY?t=271
Loscha
2023-06-26 04:35:51 +0000 UTCThe electrical equivalent of finding half a worm in an apple.
Curtis Hoffmann
2023-06-26 04:18:53 +0000 UTC
