All Transistor Clock 

Using the grid 50Hz instead of a 32768Hz oscillator and divider is cheating 😆 now seriously, I loved your dedication, and it is so refreshing to see people truly enjoying what they do 👍

One of the most underrated videos have seen Very happy somebody is paying attention to core electronics, not only high scale integration ...! I can code in binary (I learned assembler in binary, no compilators at that time ] and people look at me like I were a Martian! Your custom made 7seg are just incredible.! Some Very nice and clever solutions. A high dose of ingenuity and common sense . This video worth to watch it several times. By the way, I saw a "compact" commercial russian clock from 70s donde this way and had like 7 boatds heavy populated with components. Used a HV integrated display.

I’m slowly playing along. Sourcing second hand parts takes/makes time. I’m building only from harvesting parts. Your right. It’s an art. Love your content, explanations, and clock. God Bless.

I love electronics in theory more these days due to the smaller packaging and lack of motivation to build since anyone with youtube and a site to order modules and sensors can repair and build simple but daily money makers for technicians. As I watch your videos you motivate my interest in getting back to the bench. Through simple explanations and tips I actually learned alot of my failures alot faster than I was learning in school. Thank u and if nothing else u inspire me so please keep them coming. I would like to see some videos on different motor controllers of different motors in small packaging would be a great project to do with my son whom is currently 14 and is learning and loving. Thank u

MASTERY!!! I prostrate myself in adoration of your mad Analog Skills! Seriously awesome.

Beautiful clock. I think I'd have to watch this a few times to wrap my head around the whole thing, but it's pretty incredible what you all did with the 50hz signal coming out of the wall!

Thank you for the video. I am a Korean teenager and I like analog circuits made of transistors and diodes only. This video stimulates my desire to produce, and I'll make this watch.

I really like how you went through all of the details. I learned a lot.

You're amazing! I haven't been this excited for an electronics youtube channel in a long time. Keep up the amazing work man!

This was a great video, really enjoyed the deep understanding of a basic clock that we would all take for granted otherwise. And the digits! They’re excellent. Hats off to great build

The guitar riff at the beginning made my day! The clock info was a bonus. Thanks Leo!

Super clever solution with the divider circuit - straight from the bag of tricks!

Beautiful build. I really like the look of the completed clock :)

That red circle is genius. I'm stealing that! Thanks for making these cool videos!

Very nice design and implementation. I hope your students enjoyed the journey! The step generator looks to have potential for a curve tracer.

Fantastic! Really enjoyed the detailed explanation.

This was fascinating - I'd never have thought of this approach. And well done video too! More :-)

Darn! I learned something! Thanks. Such an interesting project. I think I'm gonna dive in on this one.

It's clever. I like it. Real 1960's technology (and ingenuity)!

The best video of my month!

Excelente projeto muito obrigado por fornecer o esquema elétrico do relógio transistor.

Awesome Job!!! You are a really good Teacher! congratulation for the result archived, for you, and your students.

you are a fantastic teacher and I think you should do series of videos starting from the basic power supply till the final 7 segment display like in 10 videos and I am sure with the way you explain stuff you can generate some funds for future projects for your students, lots of people thirsty for knowledge and how things work. Regards

This was a terrific project. Thanks for sharing

I LOVE IT IM JEALOUS LOL YOU DESERVE FULL CREDIT FOR A WONDERFULL EDUCATIONAL DESCRETE PIECE THANKYOU FOR THIE AMAZING PIECE OF ART

Great project and great video!

Very nice build. A little more voltage and a Nixie display could be added. I do a lot of non micro controller digital clock builds using old tech. An all transistor build is on the list at some point. That should get me more familiar with transistor circuits. This description will also help with more studying. Thanks.

Appreciate the detailed rundown. I want to do this now! ;)

Very enjoyable and educational video. Thanks

I love it. How I would have liked to have you as teacher !

Muito bom esse projeto

Excellent project and really good video documenting the design and build of this beauty! I really enjoyed watching every minute, and 10’s of minutes :) What level of electronics is this class? What country is your school in? The students are very lucky to have you.

Amazing !

It’s just a piece of art 😍

Great project

good work guys greetings from indonesia...

Well done very nice I love it

man, you are briliant!

excellent videos

Great video and explanation of each of the modules. Have you had a chance to post the schematics anywhere yet?

Very nice transister clock🙏🙏♥️

I *love* these videos! (Also like the Shepard Fairey poster: Obey!)

that insane !! great job

thanks Leo

Amazing my brother amazing waw

Impressive!

Nice work

Great video, I wondered How is the state of the ring counters initialized?

This is an epic project and a wonderful walkthrough. How'd you end up teaching EE in Thailand?

Genius project

I really want to build one of these. Awesome project. I don't see any specs for transformer T1. Is it homemade?

Wow! Great.

One thing coming to mind is: How difficult would it be to pwm the 100V in order to adjust the displays' brightness? I am thinking of a sawtooth generator feeding an adjustable schmitt trigger which in turn switches the 100V on and off with a frequency above visual perception. Or derive the pwm from the AC sync line in some way? Given the low power consumption of the LED Display a single transistor should be able to handle the load of the 100V line easily. Or do I miss something?

Really cool, I lerned some more about analog circuits. But two questions: 1) How do you make sure that one and only one stage in the ringcounter is on during start? 2) Why do you use a step-up converter for the LED voltage instead of simply using the 220V?

Like the divider, remind me about the put transistors.

I really would like to learn to use transistors like this, what source would you recommend

9:51 _S&M_ = "Soldering & Matrices" ? The dividers make me think of a water clock. Beautifully done.

I've been a technician since the mid 70s. I presently work for a military contractor where I test and troubleshoot a lot of legacy circuitry. I will tell you one thing, the youth of today (who has gotten an education in electronics) knows little to nothing about analog. That's because their education concentrated on digital electronics. I'm just flabbergasted over how much they don't know. You appear to be an excellent teacher, and if I had the power I'd send them your way.

The LEDs in the 1960's looked nothing like the ones used here.

Legend

I have never seen such a switching concept with a transistor, just a glow lamp. Very interesting. I'm planning my relay watch now. Another question is the conversion from 50Hz to 1HZ. Very noisy. :) Good luck with your other work.

Nice project, just one question.... What initializes the ring counters to only have one output true? Its clear that once initalized the ring counter will work as described, but It seems that multiple bits could be set, or no bits could be set... IE how do you initialize so only one bit is set?

9:50 - I prefer good old through-hole technology to S&M. ;)

Good work! The only tiny "cheat" was using the LED filaments for the 7-seg bars. Nixies, or maybe a VFD would've been more in keeping with the times.

This is increible, amazing job.

Superb video! I'm curious to know the approximated cost for all the parts and material used in that project?

Thanks for the video, this was great. I was curious what this would have costed in today's money. Given a single transistor cost at $8.00 equivalent with ~79 transistors would have been ~$630 today! Haha, I wonder how many clocks like this if any were made back then?

Is an electronic Babbage computer viable?

If you went to the trouble of a 100 volt power supply for LEDs, why didn't you go with nixies or neon bulbs to make it truly 1960-retro?

your schematic website not working ?

9:40 two transistors per flip flop? How is that possible? An AND gate takes two transistors, a NOR gate takes 3 transistors and the Inverter takes 1 so that a D type Flip Flop takes two AND gates, two NOR gates (S-R latch) and a Inverter for a total of 11 transistors.

How do you make to show the time between 20:00 and 23:59, as there is no sign for "2" on the first digit...?

strange.I tried this very same project with IC counters about 5 years ago but it didn't work as expected.and yet I couldn't get to know what went wrong.

100V boost converter : overkill ! Use diode-capacitor ladders to multiply the voltage from the transformer :-) This is particularly adapted to the low power draw of the LED.

You know ..? I am kind of rusty about basic analogic design. Now we even use an arduino to turn on a lamp ..! I will replicate some modules in my lab to refresh the ideas .!

Using LEDs, especially the very modern white ones instead of rows of incandescent bulbs seemed an out of bounds choice given the stated, albeit arbitrary, technology limit. Why no colon in the display and no AM/PM indicator or better yet, a 24-hour format? How about a laser cut diffusing lens for each display element? These are really just suggestions for the next iteration. I remember taking apart basic digital alarm clocks and finding they all used a single 0.6" wide DIP.

If you used nixie tubes, you wouldn't need the diode matrix.

Why involve such toil? How does that teach transistor tech.

you slightly looks familiar with mark ruffalo..

10:00 My first thought was you were gonna go _super_ analog -- using the phase differences between an oscillator's 3rd or 5th harmonics and the input signal to govern the lower-frequency oscillator -- with three /5 stages, a /3 stage, and then just three flip-flop stages for the /2. Fortunately not, since that would be quite insane to attempt with such low frequency signals lmao.

Как транзисторные часы на стене могут чемуто научить студентов?!

The lesson seems to be buy a clock... Cool project but a lot of work for a clock.

One strange question please ! How all this can work , along DC Power supply, ... Because all those Capacitors are not supposed to do anything in DC Circuits... ... 🤣😬🤣😬🤣... I am just a total newcomer into Electronics, but my understanding so far is that capacitors are Reacting only in RF or... AC environment , but in a DC they act Like switches in OFF position . 🤐🤐🤐🤐🤔🤪😬😱

i accidentally searched it ..

Honestly sounds better than my engineering courses

Buy=5$ DIY=50$😂😂

"... technoligy available in 1960." "... filaments from a decorative LED bulb." lol