madbeanpedals::forum

General => Open Discussion => Topic started by: Thomas_H on June 11, 2020, 11:25:59 AM

Title: New project: Signal tracer/injection pen
Post by: Thomas_H on June 11, 2020, 11:25:59 AM
Hi guys,

after some long silence I have put up speed again and I am trying out a few new things.
I set up a project to try out PCBA (PCB and Assembly) service.

I wanted to create something usefull, so knowing that a lot of support requests sooner or later have the question: "Did you use a signal probe to veryfy your circuit?" I created this:

Link to demovideo on YouTube:  https://youtu.be/C7YJBo8ySLI (https://youtu.be/C7YJBo8ySLI)

(http://diy.thcustom.com/wp-content/uploads/2020/06/IMG_20200610_172304.png)

Signal tracer/injector pen features:

Do you think this will be usefull for the community?

yours
Thomas
Title: Re: New project: Signal tracer/injection pen
Post by: gordo on June 11, 2020, 12:09:05 PM
In the teledata cable business they use a similar looking device paired with a tone generator. Commonly called a toner and wand, the toner injects a signal and the wand traces it. If I'm understanding your project, this does both?
Title: Re: New project: Signal tracer/injection pen
Post by: EBK on June 11, 2020, 12:17:37 PM
I've never used a tool like this, so I have a question:
I see one probe tip.  Do you have to pick one of inject/trace and find something else to do the other, or does this have a clip lead or something to handle the signal injection function? 
Title: Re: New project: Signal tracer/injection pen
Post by: Thomas_H on June 11, 2020, 01:06:01 PM
The device does both. It injects the signal via clip and you tip the pen to the trace/solder joint to hear if it is there.
Title: Re: New project: Signal tracer/injection pen
Post by: movinginslomo on June 11, 2020, 02:13:22 PM
That actually looks handy and much easier than trying to find a signal source, patch together your own cable with a alligator clip, paper clip and half of a 1/4 cable
Title: Re: New project: Signal tracer/injection pen
Post by: matmosphere on June 11, 2020, 04:05:15 PM
Brilliant!
Title: Re: New project: Signal tracer/injection pen
Post by: Thomas_H on June 11, 2020, 06:10:42 PM
Added link to youtube demo video: https://youtu.be/C7YJBo8ySLI

Let me know what you think!

Thomas
Title: Re: New project: Signal tracer/injection pen
Post by: EBK on June 11, 2020, 07:06:52 PM
This is a very cool tool, indeed!  Is your test signal a square wave (triangle would be a nice bonus)?

Do you have a target price point?
Title: Re: New project: Signal tracer/injection pen
Post by: gordo on June 11, 2020, 08:29:01 PM
Oh, I get it.  Yeah, that's very slick.
Title: Re: New project: Signal tracer/injection pen
Post by: nzCdog on June 12, 2020, 12:47:19 AM
Hey that's really cool... I want one!  ;D
Title: Re: New project: Signal tracer/injection pen
Post by: jimilee on June 12, 2020, 01:09:25 AM
Yeah, that is really a neat idea. Plus, I get more how to read a signal path in a schematic.

Would that be a pen you sell as a unit or a DIY project?


Sent from my iPhone using Tapatalk
Title: Re: New project: Signal tracer/injection pen
Post by: Thomas_H on June 12, 2020, 06:11:01 AM
Test signal currently is a square wave.
Unit would be prepopulated with SMD parts and you need to solder the switches and loudspeaker yourself.

I am aiming below USD 20 for the kit.
Title: Re: New project: Signal tracer/injection pen
Post by: zombie_rock123 on June 12, 2020, 07:25:23 AM
I'd be in for one!
Title: Re: New project: Signal tracer/injection pen
Post by: Rockhorst on June 12, 2020, 07:47:55 AM
Quote from: movinginslomo on June 11, 2020, 02:13:22 PM
That actually looks handy and much easier than trying to find a signal source
Use a looper
Title: Re: New project: Signal tracer/injection pen
Post by: somnif on June 12, 2020, 09:09:11 AM
Quote from: Rockhorst on June 12, 2020, 07:47:55 AM
Quote from: movinginslomo on June 11, 2020, 02:13:22 PM
That actually looks handy and much easier than trying to find a signal source
Use a looper

I use a teeny tiny little white noise generator circuit via alligator clips to the input. Doesn't do much more than hissssss into the thing, but it's enough for me to tell if sound is making it through. Not super great for delay type circuits, admittedly, or really anything where the attack and decay of a note are important, but I'm lazy and it's done its job so far  8)
(https://i.imgur.com/uQhSkJq.png)

And of course, my oh so high tech signal probe.
(https://i.imgur.com/LANrU8X.png)



This new device... yeah it seems somewhat more "fully featured" shall we say  ;D
Title: Re: New project: Signal tracer/injection pen
Post by: gordo on June 12, 2020, 12:38:24 PM
I'm good for one.
Title: Re: New project: Signal tracer/injection pen
Post by: jimilee on June 12, 2020, 01:37:47 PM
Quote from: Thomas_H on June 12, 2020, 06:11:01 AM
Test signal currently is a square wave.
Unit would be prepopulated with SMD parts and you need to solder the switches and loudspeaker yourself.

I am aiming below USD 20 for the kit.
Are the parts included or where would you get the loudspeaker? Is the tip included too? I'm very intrigued.


Sent from my iPhone using Tapatalk
Title: Re: New project: Signal tracer/injection pen
Post by: Thomas_H on June 12, 2020, 05:45:29 PM
The switches and loudspeaker are included and by the time the pens I ordered for sale arrive also the testing pins I ordered will be here and everything is in the kit.

Currently testing different speakers ;-)

I am also checking if I can get testclips like the one in the video of decent quality to include it as well but it might not work out.


Thomas
Title: Re: New project: Signal tracer/injection pen
Post by: jimilee on June 12, 2020, 09:07:11 PM
Quote from: Thomas_H on June 12, 2020, 05:45:29 PM
The switches and loudspeaker are included and by the time the pens I ordered for sale arrive also the testing pins I ordered will be here and everything is in the kit.

Currently testing different speakers ;-)

I am also checking if I can get testclips like the one in the video of decent quality to include it as well but it might not work out.


Thomas
Sold! I like the splitter for the 9v, that's really helpful in on desk cord reduction. I'm in man, this sounds like a great project. My audio probe is sorely lacking.


Sent from my iPhone using Tapatalk
Title: Re: New project: Signal tracer/injection pen
Post by: Lubdar on June 12, 2020, 11:46:14 PM
This is awesome!!!
  I rarely have to probe my pedals, but when I need to I always struggle and often just abandon the populated PCB.  This would be a great tool to help me resurrect alot of PCBs in my box-of-failures!!!

best regards
Title: Re: New project: Signal tracer/injection pen
Post by: EBK on June 12, 2020, 11:55:09 PM
In theory, could I use this as a tiny, albeit not-great-sounding, guitar amp (ignoring the square wave injection bits)?  Just a weird thought, I suppose (thinking about basic listening tests to see if pedal controls are working, etc.)
Title: Re: New project: Signal tracer/injection pen
Post by: thesmokingman on June 13, 2020, 12:44:00 AM
if I didn't already own a wire tracer I'd be in for one ... there's a ridiculous overlap in tools between my work and hobbies
Title: Re: New project: Signal tracer/injection pen
Post by: Thomas_H on June 13, 2020, 06:28:02 PM
Quote from: EBK on June 12, 2020, 11:55:09 PM
In theory, could I use this as a tiny, albeit not-great-sounding, guitar amp (ignoring the square wave injection bits)?  Just a weird thought, I suppose (thinking about basic listening tests to see if pedal controls are working, etc.)

Yes, you can. You will be able to hear any signal that is comming through the test pen - although not very HiFi like :-)

Thomas
Title: Re: New project: Signal tracer/injection pen
Post by: Muadzin on June 17, 2020, 12:18:00 AM
Seeing your vid where you describe following the signal path on the schematic I can't help but think how helpful it would be if the signal path was also shown with a similar colored line or tiny arrows on a pcb.