I am 83 years old and came across your You Tube channel by accident I started in electronics when I was about 15 years old I wish you were my instructor you are a very a good instructor I I knew how things worked but never knew the theory. I love trouble trouble shooting and watching your videos has giving me a better outlook. Keep up the good work looking forward to future videos. Merrill.
I taught myself on tube circuits, learned solid state in school, worked on equipment from the 50’s and older in my first job (anyone else seen reed type freq meters), ended up working in state of the art internet backbone equipment, and now feel old at 60 after hearing all these tube terms again.
@@JackClayton123 , Have no fear, everyone feels a bit humble after a few of Mr. Carlson's videos. LOL I'll be 78 soon myself, been there... done that stuff. Know how difficult it is, also.
Enjoyed the video. Showing my age. I've worked with gas regulators, thyratrons, klystrons, magnetrons, and traveling wave tube amplifiers during my 22 years in the Navy! The Navy is slow to change. I was still working on vacuum tube equipment when I retired in 1991 while stationed at a Mobile Technical Unit. "If it isn't broken, don't fix it" is an adage I heard numerous times.
If you were my electrics teacher in college I would have probably pursued an electrical engineering degree. Your explanations are clear and easy to understand! Thanks!
Zener diodes from 4.7 to 5.6 volts are temperature stable if the correct current is used. This is because the zener and avalanche currents within the diode cancel. Zener voltages above 5.6 volts are avalanche current dominated, which means the zener voltage will increase as temperature is increased.
Bill Harris , Exactly what I was thinking. The two different mechanisms in zener diodes is due to two different types of breakdown, the zener effect due to heavily doped diodes, and the avalanche effect due to the lighter doping. When these two effects cancel, you get a VERY rare event... a stable "zener reference diode." Very difficult to process and extremely valuable to references of all types such as current and frequency standards. de KQ2E
+TheChipmunk2008: ...SED, must be a relative of an SDR which stands for a Sight Dependent Resistor whose resistance is directly proportional to the intensity of the gaze, symbolized by a profile of an eye ball looking at the direction of the resistor with couple of arrows as in an LED symbol aiming at the resistor. Sadly, can't claim this one as my own, I got it from someone else years ago. All the best. Mark G
Paul, your such a nerd - but the world sure dose need you - your explanations of electronics in your vids is so engaging and simple even I can understand them. Please keep at it.
I have just used a Zener instead of a gas tube for stabilising a transmitter tube VFO. This morning spending my time searching for slightly wobbling frequency! Thank you for the excellent video.
+BobEckert56 Thanks for the kind words Bob! I have a ton (literally) of Heathkit stuff. Some day much of it will become video's. I have Three DX-100's just itch'n for a video.
At first when I saw this video was 31min long I thought I'd be snoring by the end. I was pleasantly surprised at how interesting it was. Good job. Found it very useful.
Mr. Carlson on the whiteboard--------time to pay attention and I might learn something. I really enjoy how you present theory, then withdraw to the lab and demonstrate what you just told us. Thanks.
I haven't actually bothered to look into electronics for years, but the way you explain things makes me rediscover an old love... Thanks for your brilliant video's. You should consider being a teacher. You're very good at it!
When in the Army, amongst a bunch of other equipment, I fixed RT-524A/VRC transievers (completely discreet components) and there was one gas diode in there because (for reasons/what circuit I have forgotten) an unwavering voltage control was needed no matter what temperature the thing was running at.
That observation alone kicked me out of my boots. Incredible! I deal sometimes with tubes, but never had opportunity to work with this kind. Interesting!
Wow, I learn so much watching your videos. Thank you for taking the time to share your knowledge and techniques. Your test equipment is off the charts!!
I am enjoying your excellent presentations, you truly do a good job. I have an EE degree and have been working in the Silicon Valley for many years, so I always smile at the subtle differences on how we articulate two words. From the US perspective, Solder is pronounced "sodder" and a Zener is pronounce "zeener". For anyone who is learning or reviewing electronics, your efforts are truly wonderful. All the very best. Cheers
Very cool demo with the gas diode tube. That is incredible accuracy for sure. It makes sense those are found in the high-end instruments you mentioned.
Hi Paul, I know this is an old vid, but thanks for it - I managed to re-learn and refresh my knowledge of how tubes and diodes work. I always struggled with tubes BITD, and you make it so clear.
You have really stepped up your game! This is a wonderful explanation of Zener diodes. To those just getting started, it may be a bit deep, but for me it is a good review. You do a great presentation so may I request more videos on tube amps. You have done some, which were great, and more is better! Thankz
+TRXBench Thanks Peter! I'm still working on that troubleshooting video, there's not enough time in the week for all this. This TTT could almost be a full time job.
Excellent instruction, I've had a tough time remembering the differences between diode types and their properties, and it's crystal clear now. Thanks a lot! Your teaching style is fantastic.
Different technologies have their preferred voltage range. The ideal voltage for a zener is around 5.2 volts. At this voltage, they tend to have a low temperature coefficient since the avalanche and zener effects both play a role and have opposing temperature coefficients. You will also notice that zeners 5.2v and slightly above tend to exhibit a sharp regulation curve. Solid state circuits tend to work at much lower voltages than thermionic circuits so it is a case of horses for courses. If you really wanted to replace an 85v regulator tube with solid state, and retain a low temperature coefficient, you could stack a bunch of 5.2v zeners to give the necessary voltage, or use a transistor, 2 resistors and a 5.2v zener to make a programmable shunt. In NPN configuration, collector to regulated rail. Voltage divider (potentiometer or 2 resistors) on base, zener (or TL431) on emitter. When voltage divider delivers more than 6v to base, transistor starts conducting. Given the poor temperature coefficient and poor regulating curve for low voltage zeners (below 5.2v), I tend to use forward biased LEDs and rectifier diodes for lower voltages, or a programmable shunt regulator such as a TL431 which, with the addition of a couple of resistors, is a superior replacement for zeners in most applications up to 36v and cost a penny. In short, zeners are cheap, easy to use but remember they are crude and have a very narrow window of precision. If you want precision, then there are solid state tecniques other than zener diodes to perform the function. The tube voltage reference is new to me, and I am fascinated in some of these thermionic and gas tube techniques. Thank you for sharing your knowledge of these older technologies with us.
Regardless what the subject matter may be, I never fail to learn something from your tutorials! Always as interesting as they are informative, I wish to thank you once again for sharing your knowledge Mr. C.!
Excellent tutorial. Brings me back to my days in the lab. One thing - maybe it's just me with a couple extra decades behind me and faulty memory - your homebrew curve tracer looks to me to be mirror flipped around the vertical axis. My memory of the IV trace of the diode would have the +V on the right and -V on the left... But it really doesn't matter - you're absolutely accurate in any case. Thanks for what you put into this.
After 13 hours of work today this was very relaxing to come home to. Very well done Paul. I enjoyed every minute of it. Thanks for taking the time to post these tutorials.And you know you just cannot beat a good ole tube. Big thumbs up.
Paul i enjoy your videos very much and I am very sorry if my reference to the compressor again I was referencing the engineering of the original flywheel not being any reflection of you or your abilities witch are both over the top thank you for your educational stuff
You have told your fans that you read the comments and as impressive as that is i would not expect any thing less your over the top thank you so much I watch most at night when I can't sleep things are kinda screwed up in the world and the more explain the circuit the more interesting it is its like not being able to.put down a good book Thanks again Paul from the epic center of the virus Michigan Thank The good Lord I have had the Pfizer shot
Excellent tutorial on the problems one can encounter with zener diodes. I ran into the zener drift issue about 20 years ago when I was building a 6.2 volt regulated supply using the zener as the voltage reference. I solved it by introducing a series JFET current regulator to feed the zener and the drift was dramatically reduced.
In my tech school in the early 70s we mostly studied solid state circuitry and didn't dwell on tube theory as much but when I graduated and got into servicing tube equipment I learned there was a lot of difference with the pros and cons of each. High powered RF applications deployed a lot of tube circuitry and were pretty durable and in a lot of ways were preferred over solid state PA circuits. The ole tube was more forgiving with high SWR versus the solid state RF amps. :)
+Dennis Petersen This is why microwave ovens don't have transistors doing the work. Transistors are very sensitive to load and impedance variations. SWR (Standing Wave Ratio) is a real issue with transistors, where tubes are much more tolerant. Thanks for your comment Dennis!
Another very interesting video once again, the tube regulator somewhat amazed me. Many years ago I was involved in the design of a power supply that had to operate over an extremely wide temperature range (-50c to +60c). One of the greatest challenges was to get the over current protection to work consistently over that range. Bizarrely a voltage reference using a constant current source and a resistor was the answer. Over such a wide temperature range the usual monitoring of voltage across an emitter resistor became tricky.... you can't just use a sense transistor to shut down the supply when the emitter resistor drop becomes greater than 0.6v. Your video helps to highlight this.
Awesome ,seeing the tube takes me back to school when I was given a tube and you have to look in the tube to identify the heating element pin ,the anode ,the cathode , the grid ,the screen grid the control grid depending on the tube given ,awesome on explaining the use of a Zener diode , love it lol I need more
i have not seen a curve tracer since the 80's in collage. since then i have used a "huntron tracker" to do the same thing, great for a quick test on aluminum electrolytic caps. great video
Paul, You make electronics simple and interesting. I wish I had you for a teacher way back when I was in Electronics Technology school. I am in awe of your knowledge and your talent for explaining things. Thank you, Thank you, Thank you. John K4AGO
NE2 pilot light bulbs also double as VR tubes in some devices. Thus, if replacing an older NE2 power-on indicator light with an LED or a conventional filament bulb, make sure the NE2 is NOT part of the power supply circuit as a VR tube!
When you need a really stable semiconductor reference, it's usually better to use a well-designed voltage reference IC like the TL431, which has a sharper knee and an adjustable "zener voltage", and temperature compensation--it's available in grades (the TL431C from TI, in SOT-23 package specifically) that are guaranteed not to exceed 16 mV reference deviation over the entire -40 °C to 125 °C operating range. The only concern then is the temperature coefficient of the resistors you use to set the output voltage (if you set it to something other than the 2.5 V it gives without the resistors), and that you can compensate for using a resistor network with matched tempco, or just really low-tempco resistors (depending on how much you're willing to spend, it's not that hard to get resistors with tempco as low as ±0.2 ppm/°C; Vishay sells them for about $6-$7 each. Very expensive for a resistor, but affordable for a one-off if you really need it). And then of course there's stuff like the LTZ1000, hyper-stable low-noise reference with a built-in heater for temperature control; stick one of those in a styrofoam oven and servo the temperature to a constant 50 °C and you basically have a metrology-grade voltage reference. They don't come cheap, though--about $70 on digikey. All that to say, zener diodes alone aren't usually what you'd use if you need an extremely stable and predictable reference voltage. They're more for when you don't care if your reference is off by a few percent and changes a bit with temperature, you just need "about 5 volts" or "about 12 volts" or whatever.
that's amazing. I have tons of gas diodes on stock, didn't experiment myself (yet), and I am totally impressed by the accuracy. We call them Stabi, here in german language. Or even Stabivolt (whioch was a brand name vor gas diodes). 85A2. 108C1, and so on.
Howdy! Thanks for the wonderful explanation. I received a MASSIVE, well for me anyhow, misc, sort of grab box filled from top to bottom with loose components. Thousands of resistors, hundreds of diodes and dozens of other components, capacitors and many that I cannot even identify, I believe go back to the days of the Automatic Electric Step in house telephone switching system. Now my old eyes aren't what they used to be, so I hooked up my cheap little microscope so I could read the codes on the tiny glass diodes and such. It has taken me three solid days just to separate the devices into categorize, and now that I have that sort done, I plan to sort the diodes into four basic groups. Rectifiers, High Speed Switching, Zener, and Shotkey. This video goes a long way into understanding why these are needed. I got the stuff from the Electronic Goldmine in Arizona. The parts are ALL top grade devices, none of the chinese clone crap, just sorting them made me feel a bit upgraded from circuit hack to perhaps a circuit builder.
I never saw and heard a teacher who explains difficult things in such an easy, clear and understandable way, Mr Carlson, Sir!! Thank you so much!!
You're very welcome!
Now it's "vacuum tubes work like a FET".
Back in the day: "FETs work like a pentode".
Another little statement that makes me feel old.
I am 83 years old and came across your You Tube channel by accident I started in electronics when I was about 15 years old I wish you were my instructor you are a very a good instructor I I knew how things worked but never knew the theory. I love trouble trouble shooting and watching your videos has giving me a better outlook. Keep up the good work looking forward to future videos.
Merrill.
Thanks for your kind comment Merrill!
I taught myself on tube circuits, learned solid state in school, worked on equipment from the 50’s and older in my first job (anyone else seen reed type freq meters), ended up working in state of the art internet backbone equipment, and now feel old at 60 after hearing all these tube terms again.
@@JackClayton123 , Have no fear, everyone feels a bit humble after a few of Mr. Carlson's videos. LOL I'll be 78 soon myself, been there... done that stuff. Know how difficult it is, also.
"Here's a curve tracer I quickly knocked up one day... with screensaver" :D
Enjoyed the video. Showing my age. I've worked with gas regulators, thyratrons, klystrons, magnetrons, and traveling wave tube amplifiers during my 22 years in the Navy! The Navy is slow to change. I was still working on vacuum tube equipment when I retired in 1991 while stationed at a Mobile Technical Unit. "If it isn't broken, don't fix it" is an adage I heard numerous times.
Vacuum tubes are not affected by EMP's - that was a big reason military kept using them.
If you were my electrics teacher in college I would have probably pursued an electrical engineering degree. Your explanations are clear and easy to understand! Thanks!
Hi Ignacio. Glad your finding these video's useful.
I was thinking the same xD
@@MrCarlsonsLab 8⁸⁸
Zener diodes from 4.7 to 5.6 volts are temperature stable if the correct current is used. This is because the zener and avalanche currents within the diode cancel. Zener voltages above 5.6 volts are avalanche current dominated, which means the zener voltage will increase as temperature is increased.
Bill Harris , Exactly what I was thinking. The two different mechanisms in zener diodes is due to two different types of breakdown, the zener effect due to heavily doped diodes, and the avalanche effect due to the lighter doping. When these two effects cancel, you get a VERY rare event... a stable "zener reference diode." Very difficult to process and extremely valuable to references of all types such as current and frequency standards. de KQ2E
So old school tubes are more stable than solid state parts, amazing. Great job schooling us ol' hacks, thanks for teaching us all.
+Sam Iam
Hi Sam, you would be surprised how much better some of the old stuff is. Thanks for your kind comment!
Thanks for keeping your youtube classes online for so long.
Thanks Mr. Carlson , you're a gifted instructor , easy to follow .
+Harry Giberson
Thanks Harry!
A diode that's massively overloaded becomes (momentarily) an SED (smoke emitting diode)
That's not smoke, it's the electrons escaping. 😉
+TheChipmunk2008 or in german language, the rectifier is called Gleichrichter. Which pretty much sounds like *gleich riecht er* (smell soon).
+TheChipmunk2008
LOL... SED, I may have to use that 8^)
+TheChipmunk2008:
...SED, must be a relative of an SDR which stands for a Sight Dependent Resistor whose resistance is directly proportional to the intensity of the gaze, symbolized by a profile of an eye ball looking at the direction of the resistor with couple of arrows as in an LED symbol aiming at the resistor.
Sadly, can't claim this one as my own, I got it from someone else years ago.
All the best.
Mark G
+TheChipmunk2008 An LED also becomes an SED momentarily, but after final collapse, becomes a DED (Dark emitting diode)...
Paul, your such a nerd - but the world sure dose need you - your explanations of electronics in your vids is so engaging and simple even I can understand them. Please keep at it.
I have just used a Zener instead of a gas tube for stabilising a transmitter tube VFO. This morning spending my time searching for slightly wobbling frequency! Thank you for the excellent video.
I wish we could all go back to valve/tube electronics. Those were the days of true engineering.
Really terrific session. Love that Heathkit voltmeter with the Nixie display. I am a lifelong Heathkit builder and now collector. A true Heathkitnic.
+BobEckert56
Thanks for the kind words Bob! I have a ton (literally) of Heathkit stuff. Some day much of it will become video's. I have Three DX-100's just itch'n for a video.
Mr Carlson's Lab I had a feeling you'd say you were also a Heathkitnic. We are a motley crew!
At first when I saw this video was 31min long I thought I'd be snoring by the end. I was pleasantly surprised at how interesting it was. Good job. Found it very useful.
Glad you enjoyed!
Mr. Carlson on the whiteboard--------time to pay attention and I might learn something. I really enjoy how you present theory, then withdraw to the lab and demonstrate what you just told us. Thanks.
Your curve tracer circuit gives that old EICO a new purpose in life. Nice!
+TerminalJack505
Old scopes need love too :^)
Nice video for a refresher for my 70 yr old mind
thanks Paul
+DENNIS N
Your welcome Dennis!
I haven't actually bothered to look into electronics for years, but the way you explain things makes me rediscover an old love... Thanks for your brilliant video's. You should consider being a teacher. You're very good at it!
+Rene Voortwist
Thanks for the kind words Rene! Glad your enjoying the video's.
All you need for zener diode training. As an added "free"bonus, I got to learn about curve tracers too. All in the time it takes to eat lunch.
When in the Army, amongst a bunch of other equipment, I fixed RT-524A/VRC transievers (completely discreet components) and there was one gas diode in there because (for reasons/what circuit I have forgotten) an unwavering voltage control was needed no matter what temperature the thing was running at.
the tube never gets under 85...amazing, and much more beautifull aswell 😆
I agree!
That observation alone kicked me out of my boots. Incredible! I deal sometimes with tubes, but never had opportunity to work with this kind. Interesting!
Wow, I learn so much watching your videos. Thank you for taking the time to share your knowledge and techniques. Your test equipment is off the charts!!
Your videos are extremely informative and very well done. Thanks for putting so much time and hard work into it
I am enjoying your excellent presentations, you truly do a good job. I have an EE degree and have been working in the Silicon Valley for many years, so I always smile at the subtle differences on how we articulate two words. From the US perspective, Solder is pronounced "sodder" and a Zener is pronounce "zeener".
For anyone who is learning or reviewing electronics, your efforts are truly wonderful. All the very best.
Cheers
Your videos are making me more and more curious about tubes. Another nice video, thanks.
+pkplex
Great to read!
Very cool demo with the gas diode tube. That is incredible accuracy for sure. It makes sense those are found in the high-end instruments you mentioned.
A very good and precise explanation. Well done as always.
+Michael Beeny
Thanks Michael!
I had no idea the tube would be so accurate! Great video as always. Thanks!
Hi Paul, I know this is an old vid, but thanks for it - I managed to re-learn and refresh my knowledge of how tubes and diodes work. I always struggled with tubes BITD, and you make it so clear.
Best short video ever. Thanks! And your Patreon subscription is worth every penny.
Again, absolutely love your video's. I like how you explain the theory and provide examples right away.
+SublimatedIce
Glad your enjoying!
Thanks, Paul. It's always nice to have refresher courses on components.
+Beretta96Dan
Glad you enjoyed Dan!
You have really stepped up your game! This is a wonderful explanation of Zener diodes. To those just getting started, it may be a bit deep, but for me it is a good review. You do a great presentation so may I request more videos on tube amps. You have done some, which were great, and more is better! Thankz
+Audio Tech Labs
Thanks for the kind words!
Thanks again Mr Carlson I really appreciate you taking your time teaching electronics. Again cant wait till next week.
+Scott Lundy
Your welcome Scott!
Thank You, Thank You, Thank You. 'Dumbing' it down to a level that I understand... Your a great teacher and your visuals are excellent.
Thanks! Glad you're enjoying the video's!
I didn't really know that much about diodes. Very informative, thanks.
+jim mcdowell
Glad you enjoyed Jim!
Another excellent starter tutorial! Take care
+TRXBench
Thanks Peter! I'm still working on that troubleshooting video, there's not enough time in the week for all this. This TTT could almost be a full time job.
+Mr Carlson's Lab Yeah Paul I exactly know what you are talking about. It really takes a lot of time. Talk to you soon!
Awesome. All your videos always make me encouraged to study more and more. Thanks for the good explanation and I appreciate.
+bee kay song
Glad these video's encourage you!
Thank you very much Paul. I very always look forward to your videos.
All my very best.
Bobby
+Bobby Tectalabyss
Your welcome Bobby!
That tube is really impressive. Holding the voltage steady. Lot of great info Mr Carlson it's a big help to me thanks for sharing.
+wade hicks
Glad you enjoyed Wade!
Excellent instruction, I've had a tough time remembering the differences between diode types and their properties, and it's crystal clear now. Thanks a lot! Your teaching style is fantastic.
Thanks for your feedback!
Mr Carlson your videos are wicked..very well explained!
Great video, Mr. Carlson. Much appreciated.
Glad you enjoyed Andrew!
maaaate that was an awesome show-down. the tube was solid as. had no idea they were that robust
Great video! ive learned so much. I never knew VR tubes were so accurate. can't wait for more of these informative videos
+Dana Vixen
Glad you enjoyed Dana!
Different technologies have their preferred voltage range. The ideal voltage for a zener is around 5.2 volts. At this voltage, they tend to have a low temperature coefficient since the avalanche and zener effects both play a role and have opposing temperature coefficients. You will also notice that zeners 5.2v and slightly above tend to exhibit a sharp regulation curve.
Solid state circuits tend to work at much lower voltages than thermionic circuits so it is a case of horses for courses. If you really wanted to replace an 85v regulator tube with solid state, and retain a low temperature coefficient, you could stack a bunch of 5.2v zeners to give the necessary voltage, or use a transistor, 2 resistors and a 5.2v zener to make a programmable shunt. In NPN configuration, collector to regulated rail. Voltage divider (potentiometer or 2 resistors) on base, zener (or TL431) on emitter. When voltage divider delivers more than 6v to base, transistor starts conducting.
Given the poor temperature coefficient and poor regulating curve for low voltage zeners (below 5.2v), I tend to use forward biased LEDs and rectifier diodes for lower voltages, or a programmable shunt regulator such as a TL431 which, with the addition of a couple of resistors, is a superior replacement for zeners in most applications up to 36v and cost a penny.
In short, zeners are cheap, easy to use but remember they are crude and have a very narrow window of precision. If you want precision, then there are solid state tecniques other than zener diodes to perform the function.
The tube voltage reference is new to me, and I am fascinated in some of these thermionic and gas tube techniques. Thank you for sharing your knowledge of these older technologies with us.
+Nick Hill
Thanks for taking the time to write Nick! Lots of great info there.
Theory is great, but knowing how things work in the real world is really useful.
+Bill Moran
That's the world I play in :^)
Very informative. Thanks for teaching me. I never knew about Zener diodes before.
+Timothy Preseau
Your welcome Timothy!
Regardless what the subject matter may be, I never fail to learn something from your tutorials! Always as interesting as they are informative, I wish to thank you once again for sharing your knowledge Mr. C.!
+Anthony Reo
Glad to share Anthony!
Excellent tutorial. Brings me back to my days in the lab. One thing - maybe it's just me with a couple extra decades behind me and faulty memory - your homebrew curve tracer looks to me to be mirror flipped around the vertical axis. My memory of the IV trace of the diode would have the +V on the right and -V on the left... But it really doesn't matter - you're absolutely accurate in any case. Thanks for what you put into this.
After 13 hours of work today this was very relaxing to come home to. Very well done Paul. I enjoyed every minute of it. Thanks for taking the time to post these tutorials.And you know you just cannot beat a good ole tube. Big thumbs up.
+The Radio Shop
Thanks Buddy! Looking forward to your next video as well! You and Peter make great video's!
+Mr Carlson's Lab You are very welcome :-)
As usual very informative , thanks Paul .. keep 'em coming ;)
+Qasim Seeha
Thanks Qasim! I will definitely try.
Great job on your video I really learn a lot I enjoy learning new things about circuits keep up the great work
+K4TEP
Thanks! Glad your enjoying.
Always something more to learn.. Thank You Paul
No Problem Wayne. Glad you enjoyed!
Paul i enjoy your videos very much and I am very sorry if my reference to the compressor again I was referencing the engineering of the original flywheel not being any reflection of you or your abilities witch are both over the top thank you for your educational stuff
No worries Paul!
You have told your fans that you read the comments and as impressive as that is i would not expect any thing less your over the top thank you so much I watch most at night when I can't sleep things are kinda screwed up in the world and the more explain the circuit the more interesting it is its like not being able to.put down a good book
Thanks again
Paul from the epic center of the virus Michigan
Thank The good Lord
I have had the Pfizer shot
Great topic and nice demonstration
.
Nice lesson Paul, thanks. I really enjoy the Tech Tips Tuesdays.
+Robert Calk Jr.
Glad your enjoying Robert!
Excellent tutorial on the problems one can encounter with zener diodes. I ran into the zener drift issue about 20 years ago when I was building a 6.2 volt regulated supply using the zener as the voltage reference. I solved it by introducing a series JFET current regulator to feed the zener and the drift was dramatically reduced.
+Richard Melville
Interesting! Thanks for your input.
Thanks for the excellent video, Paul. I particularly enjoyed the 5651 demo.
+Shaun Merrigan
Glad you enjoyed Shaun!
Thanks again and of course another awesome video loaded with info explained very well for us slow to get it guys.
+fitter108
Glad you enjoyed!
Thank you, I really liked your spot-on explanation. Please explain more of the basics and the intermediary stuff!
+Josef Seibl
I definitely plan on it. Thanks for your comment!
Flawless as usual. Thank you sir.
+YankeeIngenuity
Thanks for the kind words!
In my tech school in the early 70s we mostly studied solid state circuitry and didn't dwell on tube theory as much but when I
graduated and got into servicing tube equipment I learned there was a lot of difference with the pros and cons of each.
High powered RF applications deployed a lot of tube circuitry and were pretty durable and in a lot of ways were preferred
over solid state PA circuits. The ole tube was more forgiving with high SWR versus the solid state RF amps. :)
+Dennis Petersen
This is why microwave ovens don't have transistors doing the work. Transistors are very sensitive to load and impedance variations. SWR (Standing Wave Ratio) is a real issue with transistors, where tubes are much more tolerant. Thanks for your comment Dennis!
Always thank you for uploading video! your lecture is easy to understand
+Min Hu
Your welcome Min Hu!
Very interesting and concise demonstration and explanation ,thankyou.
Great video Mr Carlson. Thank you !!
Glad you enjoyed!
Another very interesting video once again, the tube regulator somewhat amazed me. Many years ago I was involved in the design of a power supply that had to operate over an extremely wide temperature range (-50c to +60c). One of the greatest challenges was to get the over current protection to work consistently over that range. Bizarrely a voltage reference using a constant current source and a resistor was the answer.
Over such a wide temperature range the usual monitoring of voltage across an emitter resistor became tricky.... you can't just use a sense transistor to shut down the supply when the emitter resistor drop becomes greater than 0.6v. Your video helps to highlight this.
+g0fvt
Great read. Thanks for the story!
Keep 'em coming. Just a member of your audience.
The amount of aha moments I have while watching this just makes me smile
another masterclass very good job
+design of modern life
Thanks!
wow! I alwaYslove your stuff. You do great teachingv work...so clear and helpful!
Great video and detailed explanation. Please make more videos on components. Many thanks.
Great instruction, keep it up!
+RadioHamGuy
I will definitely try!
Very Interesting, Great Video! Thank You!
+Tony T.
Thanks Tony!
Just love your videos!
+Benjamin Sølberg
Thanks Benjamin!
Fantastic review
Very good explanation and a great review
+James Silberman
Thanks!
Awesome ,seeing the tube takes me back to school when I was given a tube and you have to look in the tube to identify the heating element pin ,the anode ,the cathode , the grid ,the screen grid the control grid depending on the tube given ,awesome on explaining the use of a Zener diode , love it lol I need more
+danny blackhorse
This tube my throw you for a loop though.... it has no filament :^)
The Bob Ross of electronics. Happy little diode.
i have not seen a curve tracer since the 80's in collage. since then i have used a "huntron tracker" to do the same thing, great for a quick test on aluminum electrolytic caps. great video
+john cajka
Thanks John!
Great video. Thank you.
Paul, You make electronics simple and interesting. I wish I had you for a teacher way back when I was in Electronics Technology school. I am in awe of your knowledge and your talent for explaining things. Thank you, Thank you, Thank you. John K4AGO
You're Welcome John! I'm glad your enjoying the video's.
NE2 pilot light bulbs also double as VR tubes in some devices. Thus, if replacing an older NE2 power-on indicator light with an LED or a conventional filament bulb, make sure the NE2 is NOT part of the power supply circuit as a VR tube!
Very good teacher..... Thanks Paul :)
+joe lubb
Thanks Joe!
When you need a really stable semiconductor reference, it's usually better to use a well-designed voltage reference IC like the TL431, which has a sharper knee and an adjustable "zener voltage", and temperature compensation--it's available in grades (the TL431C from TI, in SOT-23 package specifically) that are guaranteed not to exceed 16 mV reference deviation over the entire -40 °C to 125 °C operating range. The only concern then is the temperature coefficient of the resistors you use to set the output voltage (if you set it to something other than the 2.5 V it gives without the resistors), and that you can compensate for using a resistor network with matched tempco, or just really low-tempco resistors (depending on how much you're willing to spend, it's not that hard to get resistors with tempco as low as ±0.2 ppm/°C; Vishay sells them for about $6-$7 each. Very expensive for a resistor, but affordable for a one-off if you really need it).
And then of course there's stuff like the LTZ1000, hyper-stable low-noise reference with a built-in heater for temperature control; stick one of those in a styrofoam oven and servo the temperature to a constant 50 °C and you basically have a metrology-grade voltage reference. They don't come cheap, though--about $70 on digikey.
All that to say, zener diodes alone aren't usually what you'd use if you need an extremely stable and predictable reference voltage. They're more for when you don't care if your reference is off by a few percent and changes a bit with temperature, you just need "about 5 volts" or "about 12 volts" or whatever.
Best explanation ever💯💯💯
that's amazing. I have tons of gas diodes on stock, didn't experiment myself (yet), and I am totally impressed by the accuracy. We call them Stabi, here in german language. Or even Stabivolt (whioch was a brand name vor gas diodes). 85A2. 108C1, and so on.
+Max Koschuh
Great! Glad your interested in experimenting with them.
Howdy! Thanks for the wonderful explanation. I received a MASSIVE, well for me anyhow, misc, sort of grab box filled from top to bottom with loose components. Thousands of resistors, hundreds of diodes and dozens of other components, capacitors and many that I cannot even identify, I believe go back to the days of the Automatic Electric Step in house telephone switching system. Now my old eyes aren't what they used to be, so I hooked up my cheap little microscope so I could read the codes on the tiny glass diodes and such. It has taken me three solid days just to separate the devices into categorize, and now that I have that sort done, I plan to sort the diodes into four basic groups. Rectifiers, High Speed Switching, Zener, and Shotkey. This video goes a long way into understanding why these are needed. I got the stuff from the Electronic Goldmine in Arizona. The parts are ALL top grade devices, none of the chinese clone crap, just sorting them made me feel a bit upgraded from circuit hack to perhaps a circuit builder.
fantastic video, thank you for sharing.
+Kyler Kraus
Thanks Kyler!
This is a really good video.
+notionSunday
Thanks!
Great job as usual! Thanks.
+jwl9286
Your welcome!
Excellent again.
Thanks! This showed me how I can solve an issue I have with supplying both 12 and 5 V :-)
You're Welcome!
another great video! Thanks!
+Aniol1349
Your Welcome!
GREAT VIDEO! Thank you!
very clear and understandable. thank you
+Jumper Technology
Thanks! No diode's were harmed "turned into jumpers" in the making of this video :^)
be cool to hear that 1 hour discussion of the full details of that circuit!
Very interesting, Thank you