Video není dostupné.
Omlouváme se.
Build A Cheap DIY Signal Tracer / Injector Pen Useful For Electronics Fault Finding
Vložit
- čas přidán 25. 11. 2022
- A Signal Tracer is a really useful bit of kit for any electronics repair bench. So in this video I decided to build a cheap Audio Signal Injector / Tracer Pen using some common circuits I found on the internet... That should be nice easy and cheap to do yeah? I mean, really, how hard can this be???
This video is kindly sponsored by PCBway. Please give PCBWay a try for all your PCB needs. / pcbway
If you use this link when creating a new PCBWay account and you will receive a free $5 discount coupon: www.pcbway.com/setinvite.aspx...
Music making a cameo appearance in this video: David And The Giants - Ten Miles High
Learn Electronics Repair is now on Discord! Come and join the fun, it's free.
/ discord
It takes a lot of time and effort to make CZcams videos. If you enjoy my videos or they helped you with your own repairs please consider subscribing to my channel or click LIKE
If you would like to help support this channel you could consider sending a Paypal donation or subscribing to my Patreon page. All monies received will go towards buying more items to repair and make interesting videos, or to improve my video recording equipment and will enable me to spend more time making better videos. If you subscribe to my Patreon you'll get my Whatsapp number and I'll give personal repair support
You can send donations via this link
www.paypal.com/paypalme/youtu...
You can subscribe via this link
/ learnelectronicsrepair
Thank you for your support.
Richard
That was great. I really like how it didn't work at first and you had to trouble-shoot it. Very helpful!
Made this same circuit back in 1977, in a thick pen, whilst in school. Served me very well fixing radios, casette players and amps for quite a few years. Good memories.👍👍👍👍 i think I got the original idea from an article in an issue of Practical Wireless back then.
Hi Rich, the good old multivib, I built one about 50 years ago. Worked quite well. I did use it on a couple of audio Amps as a signal injector but as it creates a square wave the audio tone sound is very harsh. What you should point out is it could be dangerous on tube/valve circuits because some of those used 2 conductor power cords and depending on the way its wired the chassis can end up live !! So that needs to be emphasized to prevent possible electric shock off the chassis and the clip that is intended for the chassis or equipment "ground" !! Yes the Cap is intended to protect the user but the clip can be the killer or dangerous lead on some devices like older radio equipment where it might get used.
Great video. Reminds me of a signal tracer I built as a kid in the seventies from a transistor radio using plans from one of the electronics magazines. Basically locate the amplifier circuit and isolate it then attach probes. I do not remember which magazine nor do I have that tool anymore but great fun when I was done and it worked. Thanks for that memory.
If you looked up the min value of hfe for the transistor you would know how much base current you would need to drive the transistor with the speaker load. Also the value of that resistor is forms part of the astable multivibrator frequency determining RC network. So if you change that you will need to increase the value of the capacitor to maintain the same frequency.
The datasheet for a BC108A gives hfe as between 110 to 200, so feeding 2mA in to the base would allow the transistor to have a minimum collector current of 220mA
great video - made a UV pen using vape pen housing / installed USB charger and the original 3.7v battery.
Thanks Richard , I learn a lot from you. Great work.
Love this Channel. Loads of great "AWESOME" TIPS 👍🇮🇪💚🙏🏼
I build a different one 45 years ago verry usefull i use it a lot
I also learned to always try a new circuit on a breadboard or even better in a circuit simulator software. In software you can easily measure all voltages and currents, make modifications and finally understand how it works if it works.
Yeah I have a breadboard and use it sometimes on videos, I thought I'd get lucky using a circuit that is all over the net and just thought i would save some time by building a small tracer I could actually use. Ho-humm LOL
That was quite engrossing. Thank you, stay well.
Nice video, I learnt a lot, including not to trust online schematics!
I imagine plugging your tracer pen into a behringer cable tester/generator (CT100?) would turn it into an injector, with selectable frequency and level output. Obviously not quite in the DIY spirit, but it is something most audio techs probably already have lying about somewhere
Thanks, very cool!
Thanks!
A few years ago I made the same thing as you made. I even used the same speaker you used, but I put a volume knob on it and I used a high voltage blocking capacitor. It's the easiest way to make a signal tracer and it is loud and clear.
Hi,
What value ceramic capacitor would you suggest? Several subscribers are asking. I don't think Richard has seen the comments. He's too busy making more videos!
@@cskeet1320 I used a poly cap. 250 volts to 600 volts are very common in most switch mode power supplies. Any capacitance will work. Most light bulbs (led or florescent) have high voltage poly caps.
The reason for the high voltage cap is for safety and to protect your speaker/amplifier if you inadvertently touch the probe to high voltage DC.
It's up to you to decide what voltage cap would suffice for what you might be working on.
@@gordthor5351 Thanks very much. Really helpful reply.
Nice one .I am always messing about with stuff like this BUT I always bread board first.it saves a great deal of time 😁
Yeah I have one and use it on the channel sometimes, I thought I may get lucky this time with a circuit that was in many places on the internet. It probably works with an 'earpiece' as it says on the schematic. It made an interesting video though and my Plan C worked well actually, and those sort of speakers can be found lying around for practically nothing at car boot sales and flea market etc, which is where they came from originally. I will be using the Tracer Pen in future videos no doubt. 😉
In my experience breadboards work ok for a while until they corrode or wear out.
I threw screaming fits when even the simplest circuit wouldn't work. Give it an enraged push and boom, it works :D
Maybe hitting them with contact cleaner every once in a while would be a good idea.
Really enjoyed this video.
What value ceramic capacitor did you use?
love it !
pretty cool to watch DIY project bro :)
For signal injection,I use an old iPhone with SIM card removed and a free app . Easy cop out but up to 15khz wave forms and free
You da man! Brother from another mother ✌️
Nice work!
I wonder how the signal sounds like in power ic like 3842 family and different power ICs?
Hello richard, can you make a video about preamp circuit? How it works, and what common fault in there. I ever meet when stereo active speaker preamp give lower signal in one side
good video Sir
Can you give the shematic of the audio tracer which capacitor did you use .
If you work on audio amps or AM radios a signal injector is one of the most usefull tools to have
i have built plenty of them the best one useing OC71 trasistors with a 3 volt supply
you can buy (from china) a flashing LED kit and do away with one LED fot the out put (you will need to change the caps to give an output of about 1kc)
the tracer did not work as it needs a peizo disk as a speaker also it would be better if it had a switchable diode detector on the input probe for use at RF .
Ceia ce spuneti dv am facut eu unul prin 72 cu Tz pe Ge si unul in 80 cu TZ pe Si Ambale au functionat ireprosabil spun au funct ptru ca de circa 5 ani sint pensionar si nu mai lucrez am abandonat tot sint satul pina in git, le - am lasat colegilor mai tineri la servici Voiam sa spun ca am adus ceva modificari evident in sensul de a imbunatati scula de a o face mai eficienta La cel vechi cu Ge am mai adaugat un etaj de putere AF in Darlington alimentat la 3Viar pe poz de oscilator la 1,5 V, la virful de contr am pus tot printr-un comutator un etaj detector simplu cu o dioda cu Ge de RF Din comutator puteam selecta urmarire in AF sa RF in receptoare MA In cel nou am impins lucrurile mai departe pe linga etajul AAF in alimentare am stabilizat U de alimentare a oscilatorului facind-o in doua trepte 0, 6V si 1,2 V era necesar si am modificat fregventa ptru a putea obtine si semnal tv comun Astfel am modificat fregventa pina ce am obtinut un numar de bare orizontala cu fond alb presarat cu puncte color RGB si bare negre iar in difuzor se aude sunetul dat de oscilator mai mare de 1Kz e un tiuit sfredelitor undeva intre 10-15 Kz Cu oscilat cuplat la o bobina cu diametrul de circa 200 mm bobinat in aer 5 spire sira de Cu cu diametru mai mare de 1,5 mm cu un capat cuplata la oscilator iar celalalt capat liber cu oscilatorul pe 0,6V si bobina asezata sub Tv explorind un canal in intreaga banda in cel putin 3-5 puncte pe canal se va receptiona o imag cum am precizat dar cu numarul de bare variabil de la canal la canal am numarat min 5 dar am ajuns chiar la peste 30 de bare (este vorba de armonica oscilatorului) nu am verificat nici o data toate canalele ptru ca nu era cazul daca receptiona aliatoriu pe 3-4 canale selectate la dif de 4-5 intre ele era, suficient si evident sunetul se aude primul cu P de volum dat la mai mult de jumatate 60-65 % pe mijloc se aude bine clar si imag oarecum stabila dar clara si distinctive barele Ce este mai pretentios trebuie totul cit mai bine ecranat, iar virful de tatonat sa nu iasa din ecran mai mult de 2 mm Virful ptru multi colegi a creat o problema dar e f simplu de facut Cumper un ac ptru umflat mingia de futbol il polizezi perfect drept si introduci un ac de cusut subtire imbracat in scchci sa intre presat usor dupa care la sf picuri in ambele capete cite doua picaturi superglue ce il vor rigidza in teaca metalica restu se intelege Injectarea semnalului se face prin poz AAF La partea de urmarire semnal RF l-am divizat in doua astfel am montat un micr comutator cu 3 pozitii 1 AAF , 2 RF1, 3 RF2 Astfel pe pozitia AAF puteam colecta doar semnal de audiofregv si asculta in casca daca erai cuplat ca urmaritor sig AAF Tot pe aceasta pozitie dar suspendind AAF si trecind pe oscil puteam injecta de aceasta data semnal in orce etaj fie radio ori tv pe pozitia de alimentare 0,6 V era suficient si semnalu nu se inducea capacitiv parazitar sarind peste etaje si cu cit te indepartezi de detectie daca receptorul este bun atunci semnalul creste de la etaj la etaj spre antena si invers scade conditia 1,2 V se foloseste la intrare in et de detectie unde semn este mic si la ultimii Tz la et final la fel si in tv in calea de sunet pe calaea com sunet imagine se merge cu 0,6 V altfel semn este prea puternic si sare etajele facind grea identificarea etajului defect La partea RF am despartit in doua intrare semnal pasiva dar cu dublare de U folosind doua diode de detectie si o intr activa folosind pe linga et de detectie in fata lui am pus un amplif de RF (TUJ) cu un Tz cu efect de cimp care creste sensibilitatea disp la peste 50 - 100 de ori ce il face aproape inutilizabil da rezultate f bune in blocurile armate cu fer nu are probleme de ecranare in rest aproape ca nu il recomand semn este extrem de puternic astfel este suficient et de detectie cu dublare de U Dupa o perioada de lucru pina te obisnuesti si inveti cum se comporta si cum raspunde ambele dispozitive incorporate in unu sing devine aproape indispensabil daca mai faci doar un oscilator pot regla media fregventa si la radio dar si tv si poate fi utilizate si in electronica industriala dar cum spuneam trebuie sa inveti sa il folosesti corect, poti identifica cond rai s-au buni cu IM verifici rezist si cu generatorul si urmaritorul trecerea semnalului evident nu poti masura valoarea dar poti sa i-ti dai seama daca blocheaza semnalu sau nu Eu l-am folosit zilnic in 50 de ani de munca nu am folosit alte instr in afara de aceste dispozitive si un IM analog sovetic f bun si precis, desi in atelier erau tot felu de scule osciloscop fregventmetre tot felu de generatoare de functii si RF Era loburatorul de electronica metrologie a unei fabrici f mari lucram in laburator 30 de electonisti dar eram singurul care ma preocupa si depanarea r-tv si desigur AAF-urile ptru sonorizari sali spectacole stadioane etc Permmanent aveam de lucru peste puteri, nu mai pot Am pus STOP gata am obosit
Nice and easy to build project i will make one for sure btw what's the value of the ceramic capacitor?
I think the capacitance is irrelevant - just there to block DC? So rated for whatever the max voltage on the circuits you're probing is.
😂 for the first time I see a real crocodile on the diagram!!
Very entertaining and valuable video. Learned now how to "design" the varioboard today. Can someone tell me what English accent he has? Where does he come from in the UK?
I can tell you I am originally from Stoke-on-Trent in the UK but I have lived in the south of Gran Canaria for the last six years.
Cool
Not first. But i ever see the schematic for the pen in your old videos.
Hi I did a simple probe with an amp. Hearing signal on certain capacitors skin. Is this normal?? Thks.
36:48
My man just create fuzz pedal
heya that's a nice diy signal finder
Hi Rich
Where in stoke-on-trent do you come from. and what size ceramic capacitor did you use. i'm from stoke myself. Sneyd green born and bred.
Nice one Rich ,KTF
thanks for video and info.. all knowledge shard gratefully accepted :) small question.. is this device basically a continuity tester?
Nope
No you inject a signal into a audio circuit for example, then use the tracer pen to see where the audio isn't. So you can narrow down troubleshooting pcb boards
@@3dsmaxrocks699 that's what my braincell has trouble understanding... putting signal and testing for reception is continuity ?? perhps my braincell needs more exercise. or my dictionary does.
@@Palmit_ if you have an old radio circuit that's not working and you turn it on (or inject a signal) you use the tracer and touch around on the input stage with it and if you hear sound you can determine where the audio is cutting out or is lost. If input stage has sound you move towards the output stages. That just narrows down where bad components might be.
@@Palmit_ continuity checks for a connection being good while tracing checks if components are good
So you’ve built yourself an electronic kitten Richard! LOL 😂! Thank you for the video and keep up the great content!
The benefits of a breadboard. ;-)
How about using a magnetic head of an old cassette player as a signal tracer
The problem with the original design is, the "speaker your using". I looks to me is not a speaker at all, it's a piezoelectric buzzer. Inside this device is a oscillator driver circuit connect to a piezoelectric crystal transducer. If you replace the device with a plain piezoelectric crystal transducer you'll find it works. That's my nickel worth. Cheers
Hmmm I am pretty sure I said the same thing myself during the video 😉
@@LearnElectronicsRepair I am sorry, Missed that.
This circuit is simply a astable miltivibrator, all beginners' favourite for flashing LEDs, but drawn in an unusual way, typically the transistors face "away from each other" if that makes sense. No idea how is this supposed to be able to trace an analog signal. And usually for optimum performance the ratio of the base resistors to the collector resistors is ~10:1, and here it is 220:1.
the astable works using positive feedback, if you remove the feed back from one of the transistors ( by way of the switch) you can then produce a very unstable amplifier, this is the basis of this 'probe' circuit.
Ahh, I see that now, thanks!
Please add downloadable circuit diagram file
Go on teen wolf😂😂😂😂😂
Who uses BC109 transistors these days?
I dont get it. Your circuit didn't work and than you went to PLAN C, put the circuit in a pen and it worked!!??
Because he used a Piezo instead of a speaker, as per the cct, it didn't work... Plan C was just a de coupling cap, signal tracer, "only" probe plugged into an amplifier...
No I didn't - watch plan C and you will see exactly what I put in the pen and what I connected it too
@@vernonmarris6076 Exactly - and that method worked far better than the circuit ever could, for practically no money, you can find those little PC speakers basically as junk these days for maybe €1-€2
Now to build the injector into the other PCBWay pen - I'm pretty confident I can do that 😉
Not working because you nees an headphoness not buzzer.
First 😁
You know when you've made it on YT, when viewers start putting First in your comments 🤣🤣
@@LearnElectronicsRepair if you start getting the investment advice links too you’ll be living the dream 👍
😂
Your schematics and explanations are very OK, but your hary fingers are odd în the video, do somthing,
Like what? Only record when it isn't a full moon?😂
@@LearnElectronicsRepair😂😂😂