Can pinpointer detecting thin chain?

[Davor]

C7 gets charged via R7, from top to bottom, and when it passes ~2.5V U3c and U3d toggle by means of a syncing circuitry. D3 accelerates discharging for the purpose of repetitive use. This circuit is a timer that switches from stabilising stage to the active stage.

Nupi, this schematic is built in ExpressSCH which is a freeware, and often used here.

[Nupi]

@Thomas

Thanks Thomas for the schematic.
Nice avatar you have.

[Nupi]

@Davor

OK, I'm going to download it and also thanks you for your schematic, it looks very nice

[Thomas]

Davor, Thanks much for the explanation, It is still very interesting, you do come up with some good Ideas.

[Nupi]

ToddB66 said to me, that he found the data from the pinpointer confused.

***He has absolutely right, I've messedup.***

I often (I mean to frequently) made mistakes.


That's why I post all the data of the PP together.


I hope this time without error.

[Nupi]

@ Davor

Is any problem when I use the TLC271 instead of CA3140? Should I change maybe C9?

[Davor]

TLC271 has an unique feature: a bias select. So you MUST connect pin8 to a steady voltage, in this case connecting pin8 (bias select) to a non-inverting input pin3 is OK. Connecting pi8 of most other opamps will result in things unexpected. CA3140 has no such quirks, and I found it cheaper locally.

[Nupi]

OK, thanks, I've started to mount, wish me luck ......

[Davor]

Good luck
You asked about C9, and maybe it'll require some extra care. There is a dependence between C7 and C9 regarding a timer period and reaching stabilised conditions, so perhaps C7 may need increasing. I designed these to reach a solution in ~1s.
I expect TR2 to be sufficient for reaching a solution. Expected behaviour is: "click!beep... beep-beep-beeeep (ready) ....." or "click!beep... beep-beep-beep-beep-beeeep (ready) ....." and the number of beeps in a row is set by TR2.

[Nupi]

Thanks for the info, Can you look at two same-numbered resistors? Number 10 is 2x. one of the drain and the other U2 pin 3. Could you give me another number?

[Davor]

Nice catch, let the upper one at pin 3 be R18. Value is OK.

[Nupi]

OK, done.

[ToddB66]

PINPOINTER - NUPI - 2014 - Final

nupi,

Have you built a working model of the "PINPOINTER - NUPI - 2014 - Final" ? Would like to see a picture of the completed PP installed in the housing if possible.

Thanks,
ToddB66

[Nupi]

nupi,

Have you built a working model of the "PINPOINTER - NUPI - 2014 - Final" ? Would like to see a picture of the completed PP installed in the housing if possible.

Thanks,
ToddB66

Hi ToddB66,
I've made a lot of PP. Most are sold. I can take a picture of mine "workhorse" Nupi PP MK2. It is slightly larger than the normal NUPI PP but he has more depth than the normal NUPI PP. 16.5 cm with one euro. I still have empty housing and parts of NUPI PP, I can take a picture of it if you want, I'll see when I have time for

[ToddB66]

Hi ToddB66,
I've made a lot of PP. Most are sold. I can take a picture of mine "workhorse" Nupi PP MK2. It is slightly larger than the normal NUPI PP but he has more depth than the normal NUPI PP. 16.5 cm with one euro. I still have empty housing and parts of NUPI PP, I can take a picture of it if you want, I'll see when I have time for

Nupi,

Re the "normal" NUPI PP, please send E-mail to me at toddbrock@frontier.com with picture, price including S&H and key features for (1) NUPI PP.

Thanks,

ToddB66