EEVblog
ฝัง
- เผยแพร่เมื่อ 1 พ.ย. 2015
- Bumper Mailbag.
Guest appearance by Sagan
Forum: www.eevblog.com/forum/blog/eev...
SPOILERS:
Sinclair / Thandar SC110 10MHz portable analog CRT oscilloscope form the 1980's!
Makerbeam by Chartup: www.chartup.com/index.php?cPa...
A mystery device from a Police auction from Rossin Corporation
10MHz TCXO reference clock generator: www.bloguetronica.com/2015/08/...
AST3TQ TCXO datasheet: www.abracon.com/Oscillators/AS...
CC2541 Bluetooth microcontroller datasheet: www.ti.com/lit/ds/symlink/cc25...
Fitbit ripoff teardown
MMA955L Motion sensing pedometer datasheet: www.freescale.com/products/sen...
Harbour Freight Cen-Tech multimeter teardown!
EEVblog Main Web Site: www.eevblog.com
The 2nd EEVblog Channel: / eevblog2
Support the EEVblog through Patreon!
/ eevblog
EEVblog Amazon Store (Dave gets a cut):
astore.amazon.com/eevblogstore-20
T-Shirts: teespring.com/stores/eevblog
Donations:
www.eevblog.com/donations/
Projects:
www.eevblog.com/projects/
Electronics Info Wiki:
www.eevblog.com/wiki/
💗 Likecoin - Coins for Likes: likecoin.pro/@eevblog/dil9/hcq3 - วิทยาศาสตร์และเทคโนโลยี
Dave, Germany isn't on the other side of the planet. Australia is.
Greetings from Germany.
Ahahahah you made my day
haha, greeting from Australia..
+Friedrich Ganter I am at the perfect middle between you too so I will have to decide who is on the other side. Incidentally my location (26°16'47.46"N 87°53'18.84"E) is perfectly at the center on the connecting lines of you two. Greetings from India.
+Friedrich Ganter The antipode of Sydney is a 1500km or so west of the Straights of Gibraltar.
Thankfully for Australia
35:10 I agree with you 100% when comparing this "Free" to $5.00 cheap meter to a $200 Fluke.
But there are a lot of new young budding electronics engineers out there that just can't afford a $200 Fluke.
37:30 If you use the meter under 50V and a max amperage of 5 Amps this meter is accurate and safe enough for electronic/arduino type experimenting. We use these cheep meters in the shop as throw away quick checks and the Flukes as precision accurate and higher voltage use.
All you seem to have done is let the younger players feel that they are idiots for using a cheap meter like that when in fact it is quite usable and accurate.
Exactly
I think the same and more: the ones surprized by the precision of cheap multimeters are idiot enough to don't contrast them with their 'great' multimeter's precision and it's many times the same 0.5%. Funny when they take the expensive multimeter for precision and many times its the same lol
yeah but it's good enough to check a double a battery
I don't think he was deriding that multimeter or saying it is junk, yeah he was kind of negative on it but was impressed with it's accuracy and low price. But he didn't give out a flat recommendation not to buy it just pointed out that it's a bit dodgy for non hobby work
Here In india, I have seen in all the repairing shops in my hometown they use this multimeter for working with both dc and ac voltages(230 Volts)😥😥
I love the free Harbor Freight multimeters. I get one every time I have a coupon. Of course they are useless for any precision measurements, but I can hook up two or three of them to various spots on a circuit to see current draws, voltages, etc. during troubleshooting.
That Rossin item is a single-beam PIR - single beam here meaning one detection zone - and PIRs are something I know about, having designed a few in the '80s.
Rossin was a US firm whose speciality was ultra-low power PIRs running off a single 3V Lithium cell and I just happen to have here the cct of their W60 I traced back in '85.
The chips should be a pair of CD4001Bs and the remarked one an MC14573 quad programmable op-amp. The L & C terminal are the output, drain and source respectively of the VN01 MOSFET. The cut resistor is probably the means of switching from NO to NC output - the W60 had a link. The Iq of the one I traced was 400nA so this one may still be working.
The IR sensor is a funny with only two terminals, not the normal TO-5 with a silicon window three-terminal one. Unfortunately there's nothing about it on my traced cct.
If Dave asks nicely I'll scan my hand-drawn cct and notes.
+Graham Langley Found I've got the product flier. It's either the R50 (wide view) or the 70W40 (long range - 21.5m). Battery life is given as 15 years.
+Graham Langley The memory has dug up that someone had a patent on using a faceted mirror in PIRs to generate multiple detection zones - this was before HDPE Fresnel (that's 'fren-ell') lenses came along.
It might be that the Rossin PVDF(?) sensor has multiple elements and so only needs a simple convex mirror.
.
It's an Rossin corporation R-50 THERMAL INTRUDER SENSOR
Still available as surplus stock :
www.radwell.co.uk/Buy/ROSSIN%20CORPORATION/R50?redirect=true
.
sign of good parenting, your kid moved their hands away from the knife
I noticed that too. Top work Dave!
I had an SC110 scope from new - at the time it was about the cheapest new scope you could buy. One of the transformer overwinds is for the filament - done like that for either HV isolation or low capacitance.
Thandar was Sinclair's test equipment division - changed the name & split off when Sinclair went into computers. They later merged with Thurlby to form TTi. I met someone recently who worked there at the time - some of the old guys are stil there at TTi
+mikeselectricstuff Thanks for the info Mike.
+mikeselectricstuff One of the electronics mags around at the time did an article on the circuit design of this. Can't remember which one and my copy may have been recycled some time back.
Edit: Just remembered a couple of things. The case was borrowed from something else and wasn't quite big enough internally to accommodate the flare of the tube, so the walls had to be milled out to make room. And the rechargeable cells they sold for it were AAs in a C-sized sleeve, which you only found out after you'd bought them.
Honestly though. Those cheapy multimeters are pretty reasonable for everyday use. I think in this day and age it's pretty easy to make a reasonable multimeter that would work perfectly fine for hobby level projects for pennies.
That said if I had to mess with any actually high power stuff, that would not be my first tool of choice.
The wife and I love the videos with Sagan. He's an awesome kid and smart like his daddy!
My father was given that Harbor Freight DMM (in yellow) as a door prize, just for walking in during a promotion. He complained that it had malfunctioned, and that sparks shot out...upon further investigation I can't really fault the meter as my dad tried to "test how many amps the kitchen circuit was" by putting it in the amps range and sticking the probes in a wall outlet!!! LoL I told him I'm glad he's still living.
The failure mode was 3-fold: The fuse charred (probably still passing mains), traces on the board started to lift and blacken, and the black probe lead failed open.
Miraculously, with a new fuse and leads the meter seemed to work just fine!
I warned him to keep it away from outlets, and removed the traces to the amps range to help protect my pops from himself in the future.
+Stephen Tack
Well, I did it with Fluke 333 on ohms range. Twice! The result: 2x burned 16A fuse (ceramic 220V/16A) + set of burned leads. The 333 is unharmed and happy. Me to.
zlotvorx fool me once...?
Love this post Dave, reminds me of when my boys were young. Hope I meet you one day in Castle Hill Towers as we go there often. Would love to shake your hand...lol.
My father was an Electronics Technician and was almost as good as you are introducing me to the physical universe as you are to Sagan.
Thank you for your authenticity.
Live long and prosper my friend...and if time seems to be passing too fast, remember 88 miles an hour can bring you back.......
Sagan's Australian accent is adorable! great video as usual Dave!
+iTsTheVoLtAgE Sounds a bit English to me. Is his Mum an Aussie or a Pom? (Cute either way.)
Grew up using these cheapie meters. I've still got one lying around, except mine has *gasp* a backlight!
I've got that meter too. I'm still using cheap tools and salvaged parts. That was my first meter, and its actually my favorite.
+Alex Kantor And I paid like $10 for that meter!
+RadRider33 yup, still have one myself, good 10 year old design. But it works! and it's better to have a multimeter than not have one (and I don't really do in electronics to have requirement of better than like 5% precision)
+RadRider33
I have a Harbor Freight about a 1/2 mile down the road .... Whenever they go on sale for $2.99 I pick a couple up. Got one in my boat, my truck, my car, next to my main desktop, the garage workbench and a couple sitting on a shelf unopened. I don't even bother changing the battery because the cheap leads will be on their last leg and break before the 2nd battery goes dead. I just pitch it and grab another off the shelf The leads used to be a lot better, larger gauge and better insulation , no way would I trust the new ones to take 10 amps, the resistance of the leads would be 10 times or more than the shunt and the measurement worthless anyway
Good enough for 12V boat and auto circuits, testing batteries and continuity checking although I think they should just ditch the transistor tester and add a continuity buzzer on it's place
+RadRider33 that design was my first multimeter too. got it like for 6 dollar local currency equivalent like 10 years ago. Mine died sadly (numbers jumping for no reason, no measurements on any range), lead broke somewhere inside. Still have it as my first dead measurement instrument.
PS. Sagan is going to be a bit of an Einstein compared with his peers at big school.
Definitely! the way he speaks rivals many adults lmao
+mart fart He's going to go to school and tell all his friends about his 10Mhz reference oscillator!
Dave, I wouldn't bother with a pension plan. Sagan's going to be wealthy chap - who'll be able keep you in style during your old age ! ;-)
Speaking of Sagan I've not seen him in a more recent video in a while it may just be that I haven't happened run across one a little bit but just thought I'd mention it have not seen too many Eevee Blog videos recently so might be part of the reason for this. Also anyone know how old saying it is at this time? And yes I remember project Seguin of course and also the other kiddo of his as well course I thought that was hilarious when he did that that was the way to go I believe especially since the type of work he does what a way to introduce the new family member to the world. Also I once knew some way that work for a company that designed toys years ago and they did something similar when they had a new kiddo in the family it was basically a fake doll type of reveal I thought of that when I saw project Seguin although the doll thing was years and years ago but I still remember seeing it on the Super 8 film when they did the reveal to the family yeah it was that long pre VHS
When Segan is in his teenage years or so, he'll be able to look up old footage of his early childhood on TH-cam...
Kinda weird if you think about it, the first really "digital" generation post 2010's
+Osmosis Scary. I've got practically nothing from my childhood. Just a couple of photos.
+EEVblog Your son is adorable.
+Osmosis I'm 25 and I even I still find this a bit scary. The oldest footage I have of my childhood is all recorded on cassette tapes and faded images.
+Osmosis i dont know if weird or disturbing how easily everyone will be able to look up all your embarrasing moments digitally at typing speed, in our age you'd have to dig up some old VHS-C tapes(if someone was even filming in the first place) -pray they're labeled properly- and essentially watch the entire thing to find out something or clumsy FFWD, maybe a photo album.
Now with a camera/video in everyones pocket ready to record in seconds, failarmy and yt every blunder with haunt you forever :D
+Osmosis And he'll be reading these very comments. How spooky.
I used to watch my dad work on electronic projects at his bench. When he went to the electronics store on a saturday it was like christmas! I dont do much with electronics like he did but still enjoy putzing around with things of that nature. I find myself doing more electronics than ever now that I am back into RC Planes and lighting my plastic models as well as my planes and helicopter.
I love when Sagan show up! Very nice!
Really enjoy the mailbag episodes with you two!
Wonder if the rossin thing is a beam-break detector - that would explain the lack of facets (though may be a faceted lens insid the copper can) . Battery may be to provide pulse power due to 2-wire connection, or maybe biasing the sensor
+mikeselectricstuff Thermal Intruder Sensor? www.ebay.com/itm/Rossin-Corp-Thermal-Intruder-Sensor-6678-/131405385387
(don't mind me, commenting before finishing the video...)
+mikeselectricstuff Nope, it's a PIR.
+mikeselectricstuff i think is that or signal jammer
It looks like this: www.google.com.br/patents/US4468658
These cen-tech meters will report different readings based on the battery voltage. Some may consider this a fault, but I think it is a feature.
+Macpod HOW IS THAT A FEATURE? (caps lock, to lazy to re-type)
like.... how could that be useful besides confusing your friends? here use this meter, its 100% accurate.
if i let off the gas quickly in my truck it pops out of 3rd gear... thats a feature, it shifts for me!
+kain hall It's a subtle feature to let you know this meter is garbage, mate :)
It's a battery gauge, you connect it to precision voltage reference and depending on voltage shown by meter you know how much energy is left in the battery.
I have one of these. The useful thing is, even when the battery is completely dead it still measures 5.5 ounces.
When the battery dies, just go pick up another free one. :-)
Sagan is fantastic. Great to see him getting into that MakerBeam kit. Way to go, and greetings from Seattle, Washington (specifically Kent, Washington)!
Enjoy him! Time goes so fast. My last one graduates this year, WOW it seems like yesterday. Cheers
My niece is around the same age and she also started going to school 2/3 days ago. Hopefully she's enjoying the experience.
A white phosphorus version of that oscilloscope CRT was used in some portable TVs during that time.
I remember in High school electronics class we a like 7 or 8 of those 7 position Harbor Freight multimeters and two or three Triplett 630-PL meters and almost everyone else preferred to use the Harbor Freight meters but whenever I could I used the the Triplett. I loved those meters.
Hah! I thought my mail got lost in the post! Great 2 min teardown! :-) Greetings from Ankara/Turkey.
Hi Dave, Love it. My dad 'lent' me one of the Thandar scopes in the early 80's It was branded RS Components (UK) and as I recall it cost just over 100 UK Pounds at the time. It was part of a series that included a matching frequency counter and multimeter. It finally packed up about 10 years ago, and I'm ashamed to admit that I still use the probe that came with it! I used it to trace trigger card faults on thyristor lighting dimmers and the fact it was 'ground' free was really useful. It started displaying the same issues you discovered about 10 years ago and finally died soon after.
I've been using that Cen Tech multimeter for several years now, still works like a charm! Mine was free with a dollar purchase of tape. The leads broke at a point, but I fixed them with some solder and hot glue. No problems with the meter itself!
great video! He can follow directly in your foot steps.
What a clever boy Sagan is! You must be a very proud dad dave! I'm sure he'll grow up to be as much as a legend as his old man!
I can already imagine the teacher calls Dave and telling him "I sent him to play with the other children and after five minutes I saw him taking apart everything and all the kids shouting 'Don't turn it on! Take it apart!' "
When I was Sagan's age, I unscrewed wall plates off of the wall.
Did you have a multimeter with you to check them out and then if they weren't working right fix them not lol for me when I was old enough I would be fixing problems the people didn't realize I had right then and there if I had the parts of a whole I kept electrical supplies with us in the car you'd be surprised when someone when asked could Aaron take a look at that lamp Outlet whatever I'm like sure where is the electrical panel so I can shut off the power if need be also the reason why I had a hundred twenty volt powered Boombox in the car and find out what circuit so it was on they did not have breaker fuse finders back then but there were times which I couldn't kill something I'm very tempted to crowbar the thing a k a dead short did that once and guess what well couldn't kill it but what are the neighbors knew I was working over there and came running over and they said how far lights are flashing I'm like what is going on and I noticed that it seems like there's a lot more energy than just it may be a single circuit turns out this was range wiring or similar it had completely bypassed the service entrance all together it was running to the meter box directly found out later bypassing the meter entirely along with us which we could not figure out that they noticed that sometimes you want to throw was extremely low and our times very high that switch was turning on and off the voltage coil do drug terminals on the back of the meter where there was a link that could be removed on those old meters so another words whoever originally had the place was stealing power obviously not the first time I've seen crazy things like this also unenroll metered water service that have been abandoned and reconnected and the horror a place that had never had Natural Gas officially but had gas appliances and was working but there was a meter that was hooked up to the gas lines lighter for these except not all of them we're actually metered but they have been using about turkey for the longest and didn't even realize there was gas present even without the meter up and to the point they smelled gas the gas company try to show it off but there was still gas on to certain appliances.
Also I've seen places where there was natural gas service but the utility company said there was never gas service to the place and there was no record of any connections whatsoever.
And also and there were times in which there was a house that have been built and there was never any gas but there was a gas line coming into the foundation that was connected at the other end and not being able to be shut off and the people thought they were crazy because they smelled natural gas but new Dr was never any girls was looking around and I spotted I can't turn off pipe in the foundation sure enough gas line leaking.
That little boy is so awesome and cool....
They sell those multimeters here in the Philippines for 120 peso (2.5 USD). And that's in the mall! So imagine if you bought them in bulk :P
+Gadget Addict less than a dollar in china :-)
www.alibaba.com/product-detail/High-quality-professional-digital-multimeter-DT830B_921274538.html
+Gadget Addict CD-R-KING!!!!! hahahahahaha
Thurlby Thandar was a company that joined with Sinclair Research and indeed some of Clives calculators ended up in Thandar cases. They were both in Cambridge of course and there was a fascinating array of product made by that pairing.
I have gone through at least 5 of those Cen-Tech multimeters. I have never had to change the battery. They blow up before I get to it. Wear the right gloves and it can be safe enough. The case holds in most of the pieces of the pcb and battery
sagans gonna be a damn good engineer growing up in your lab. that's awesome that he's already interested in it at 4
I've had a Cen-Tech meter for several years and surprisingly it still works, mine looks almost identical to the one here except it has a backlight button in the upper left area by the DCV label.
Have been trying for years to get those modular beams from Bosch Rexroth, can't find them anywehere and Bosch doesn't even answer to consumer emails. But Sagan is the first kid I have seen putting things back were they where (winding the wire back to the spool) instead of taking everything out! Good job Dave!!!
Sagan should open a few parcels every week love the little fellas enthusiasm.
Got one of those multimeters for free from Harbor freight a few years ago, wish I had read the instructions the "do not operate tool under the influence of alcohol or drugs" part is great.
the Rossin device that you showed on # 813 is a passive infrared sensor for a burglar alarm. It is intended to be wired in a normally open alarm loop. the battery actually powers the device and i think it should last for ten years . I used some of these probably 30 years ago. will look to see if I have any info on it. Love the Blog. Thanks for what you do.
Very cool episode, Dave. Sagan is just precious.
It's so interesting having Sagan helping you, nothing like a child to help out, they always have interesting comments.. He's quite the geek already, just like dad...
I love Sagan's english accent...?..go figure Dave
+MacVision Could be Pepper Pig and Mr Maker!
+EEVblog Peppa Pig seems to be really popular nowadays.
+MacVision sounds exactly like all of my nephews, must be pepper pig
+MacVision Exactly what i was wondering about. As a non native english speaker i thought i maybe mistaken it, but obviously i´m not :D
+MacVision that will disappear when he starts school
It's PIR, I used very similar units made by Racal back in the early 80's. It had an operating life of about 5 years, and used the on board battery. After the unit detected motion, it would "sleep" for a period of time, to save battery life. That unit was clearly a single narrow beam type sensor.
Mailbag, the best 49:49 of the week.
Drinking iced coffee and eating crispy doughnuts.
Love those free meters. I have them at several at friends houses. Several here. If one blows up no problem.
The breathalyser is probably a generic flammable gas detector. It consists of 2 wires, one coated with a catalyst, and one not. They are wired with 2 resistors in whetstone bridge configuration. The wires are heated by a small current, but normally remain balanced. If there is alcohol on the breath, the catalyst oxidises it, and adds heat to the catalytic wire which increases in resistance unbalancing the bridge. All you need to do is measure the bridge imbalance and if it is over threshold turn on the light.
10mhz for that scope is damn good, i got myself a "old" analog scope here with only 1mhz bandwidth. probably with tubes inside havent it taken apart yet.
The Rossin thing looks exactly like the one my friend had in his house back in the 80s, I think it had a send and receive on either side of the hall way, I remember having to slide under it when we would skip school and go to his room to play video games on the Atari lol
love how Sagan realised the spool holder before his dad. :) wonder if its because he saw the picture earlier and put two and two together subconsciously.
clever kid! :)
I was thinking either and hello or possibly a cable holder and then I realized oh wire spools
29:07 They called that a "Thermal intrusion sensor" if memory serves correctly. I picked one up at an auction in it's box...but threw it away.
Of course I couldn't figure out how to use it? Or just so odd? Please elaborate in a comment
They don't practically away, they do just give them away. With a mail/online coupon you just walk in no purchase necessary and show them the coupon and they give it to you free.
Love the Crocodile Dundee knife. "That's not a knife mate. THIS, is a knife."
Have one of those multimeters for 10 years now and works perfectly. Nowadays I have a Fluke 179 and I like it but to be honest for my needs the cheap China multimeter would do the job perfectly. Highly recommended
Re: Cen-Tech multimeter.
I bought one of these 6-7 years ago. $3. It has rattled around in the tool box all that time, and always works. Original battery. The transistor tester is useless, but the battery tester is not, I use it and many other features most every day. Recently, the probe wires wore out, and I elected to buy new wires rather than a new meter. For the average person, it is fine. Every value I have been able to cross check is reasonably close.
I agree. I know why he is bitching around. I don't care if it is 9,99 V or 9,998563727363738 V
I have one of these. It doesn't measure anything external, only the values of the internal components. It's useful in that respect.
Keep it away from high voltage, absolutely no protection in it. Otherwise it's great for checking batteries and ultra basic diagnostics.
As someone who barely knows what he's doing it's good to let me know if my better Radio Shack meter is working or if I'm doing something wrong. I bought it for the transistor tester which is not great and because at $3 how can you not.
I got a few of those HFT mulitimeters (for free). I was thinking of taking the thing apart so I could embed the multimeter as a voltmeter in a home brew power supply. I'd have to some how wire the lcd to the board with ribbon cables and short the right lands on the range switch for the desired voltmeter range. I might even be possible to cut the main board down a bit since I might not need all of the circuitry on it, I'd have to trace the layout out and figure it out. The thing just might make a serviceable DC voltmeter for a project.
I've got that multimeter, which is why I was particularly interested in this video. I thought you were going to say it's a death trap. I'll keep it away from the mains per your advice though. I've got another multimeter I can use for that, and I know that one's safer because I actually had to purchase a SEVEN dollar torch to get it.
Clearly Sagan takes after his mother; his diction is very good ;-)
+James Brown I can't be the father, getting a paternity test immediately!
+EEVblog I don't know, he seems to love your work when you bring him! should be very proud!
By the way did you try Golf and give up username? Story behind it? Please call me at not a? But an explanation point
That Rossin device is a "thermal intruder detector'. Basically an early PIR sensor.
Yep
It's basically the standard Mastech DT830B except all the Cen-Tech ones have the battery tester with a switch where as the other DT830 devices usually have the knob control the power and no switch. Some of the Cen-Tech multimeters even have Mastech molded into the plastic of the lead ends. If you're planning on giving it to Sagan, make sure you didn't loose the two ball bearings that are in the knob. I saw them fall out when you were rolling it around.
IIRC the switch on the alco tester is just for the light. To measure your alcohol level, hold the push button depressed until the green led lights up, then blow gently onto the sensor.
that cheap multimeter... tell you what its handy for random small jobs and better than a bulb with two wires.
A bulb with two wire is often better for testing automotive circuits.
I have one of those just for continuity and reading voltages on where i don't have any idea of how much tension it is (and don't give a fck if i burn it haha)
@@TheCode-X The gadget is not what you should be concerned about. The worry is about the effects on your person of its explosive disintegration by massive overcurrent.
Speaking of a bulb with two wires I used to have that same setup for testing voltage when I first started out you're doing electrical projects it was one that was handed down to me from another family member.
It was homemade but still in good shape even with the original test leads that probably had been re-soldered a few times originally one was red and one was black but one had to be replaced.
From what I was told and I also had a second one that is made by the same person that had longer leads but had two bulb sockets so that it could be used anywhere from 120 volts up to 220 Ameri fact I remember hearing about in some way somehow possibly from different sources how's that the utility company when connecting up to a residence when running new wiring for overhead lines Wood Lamp out to connections at the service entrance from their wiring to the service entrance whenever first connecting using a setup very similar to that also I still have a continuity tester flashlight that was given to me years ago is still works although I did converted to an LED it still is a nice flashlight also somewhere I still have a few of the old from colored not necessarily chromed but I think one or two are metal C or D cell flashlight I think a couple r c and a couple Rd also have a few lanterns stowed away somewhere that would have used the racial big 6 and 4 volt batteries I'm thinking about converting them some way to recharge mobile maybe you're sealed lead acid and perhaps a built-in power bank?
Although I do have one Lantern or two that had a quarter inch track originally on there one even had two of them perhaps one was added?
So that you could use it with a headlamp in addition to your Lantern and yes the original coil cord is still in good shape believe it or not.
And there was also an area like that could plug into the second Jack.
There was a switch for both receptacles and also a switch on the lights themselves as well.
Can't remember if that was a 6 or 12 volt Lantern but I think that one was 12 it's stashed away somewhere but not where I am right now.
Also have a land foreign pride of similar except it's got a cord and 2 rounded is 1 would Connect into the front of the lantern in place of the Winds and reflector assembly and the other is essentially the head of the lantern that the bulb in reflector assembly goes into to turn it into a hand Lantern from a battery pack type Lantern again it was one that took the large alkaline or whatever it would have either been 6 or 12 volt battery you know when the big Lantern batteries they don't see much anymore.
Also I do have some sealed beam 4.5 volt Lantern bulbs don't even know why I have them are where I got them possibly an old hardware store did they still sold those lights and may have closed down but don't know we're no longer sold the lights who knows just one of those random things I got over there years at places that could get stuff from cheaply where is somebody could have been used for something else and sometimes when something like that would come up I could arrange to get all of them Ford even further reduced price especially if I knew the business on her well in which law of cases I did that I was known for picking up stuff that there's only a few things left an inventory they're getting rid of Good Times those times I'd say.
@@stephenarling1667 yes I would agree I have one of those testers which is actually a modified Automotive work light modified in terms of a jack with test leads and another Jack with alligator clips for battery and our Jack with the cigarette lighter connector I Know Jack with female banana plugs
And also a set of very long coiled test leads with male female banana connectors.
Is that should be in everyone's test kit does extension lights same with alligator clip to Banana plug leads and just about any other type you could think of or come up with even if you make it for one specific test put it in your test kit for lighter you will thank yourself for this.
Also speaking of a bulb and Automotive there's times that I did not have the proper materials or tools to do testing and what I would do would just pick up a pack of pull volt indicator lamps the ones that would be worrying that had the blue green or whatever colored plastic around them that was meant to snap into a hole in a panel and just attaching wires it works plus you had indicators for another project in the end one time I even round up using a switch with a 12-volt bulb in it because I could not get an indicator but I could guess which or it was just a viable I don't remember long time ago but I was in pain and it worked I was able to get whatever it was working it need to be to under right then and there.
Also if I was working on something for somebody and did not have a proper meter or continuity tester available I would go somewhere and get a battery holder and an indicator of some sort with nibia 4 volt bulb and maybe a 4 C or D cell or double A or AAA holder and make a Jerry Reed continuity tester out of it and then of course save for parts for another project later I fixed a hair dryer doing that once all that was wrong was there was a broken piece of wire between two points in the device this was actually not the handheld dryer but a Hood Type dryer a very expensive one and the person used it all the time and wondered if I could try to fix it for them Ameri fact the wire need to be high temperature and that was salvaged from something else that I could not fix during about the same time can't remember what was it may have been either a heater or a toaster or perhaps a little mini countertop stove I had prepared several things for them previously was in about a month's time so can't remember but this was many many years ago probably in excess of 20 years but yet the mind is still sharp pretty much Seems Like Only Yesterday that I got my first electrical tester of any type.
By the way was going through some stuff and found my first actual continuity tester that I had gotten from somewhere yeah sure the batteries were left in it corroded do you know where however once I get cleaned up it's going to live on although I already found a way to replace this the original spring which was corroded into two pieces which was the new spring was actually a salvage spring or something and two metal pieces I think that were a battery contacts for something recently folded over on either end of the spring and also they fit exactly without even stretching the spring or anyting so just pretty cool what you can do or salvage parts and also things that you jerry-rig even for one temporary use just to fix one thing.
I've had one of those el'cheapo multimeters for over a decade, just for testing 12V batteries and stuff. Always baffled by the transistor tester though.
So far, I own 4 of those free Harbor Freight Tools multimeters. At first I figured they would be very inaccurate, but was surprised at the accuracy. I also figured they would be unreliable, but so far they're reliable enough for use in non-critical measurements.
I keep one in each vehicle, monitoring the battery voltage, and after several years, they still do a good job. They even give good readings at 30 degrees F below freezing and 120 degrees F.
I've had them read incorrectly about 2 times. I quick rotation of the switch, and they're reliable again. I only use them when I already know what reading to expect, so I can tell if they are off very far.
Not to be fully trusted, but still useful.
I so in a early magazine article that Sinclair made this Oscilloscope from using the TV tube from his failed portable TV.
I have one of these bought from brand new.
That "free" multimeter looks like one I borrowed from a friend to help me fix his friend's TV set. Fortunately it was adequate, and it was just a failed fuse with no obvious cause. I had the set working again in under an hour, including going to a shop for the part. Transistor sockets are definite frippery.
Those cheap multimeters are perfect for checking battery voltages, or continuity (if your model has that feature). I have dozens of these laying around. I do have a couple good meters but they don't get used unless I need precision. I used one of these recently to diagnose an electrical fault in my car, worked perfect.
Bright young lad youve got there! Glad to see him super interested in everything!!
aww thats is too cute... you should include him in more videos. What a good father/son moment. Awesome dave, just awesome.
I've had quite a few of those HF meters, some yellow, and later ones red. I was reading voltages on a 480V VFD (supplied via a small transformer) and accidentally had it on ohms rather than VAC (knob was turned 180 degrees), and I heard a little "pop" and perhaps saw a little spark, and the meter was thenceforth DOA. They are amazing for the price (free!). My main gripe is low ohms zero usually 1-2 ohms minimum, mostly because of the cheap rotary switch with non-gold-flashed tracks.
Glad to know the only multimeter I have is BANG ON. I truly was curious of its accuracy. Ashamed to use it though. Lost my old analog ones...
Those Harbor Freight meters get put to another use: A Field Strength Meter! Conversion article on page 71 of the February 2015 issue of QST Magazine.
Better check that wrist strap and make sure that it employs the 1M resistor :D
I have the 92020 version of the HF which includes a gorgeous orange backlight and is surprisingly accurate. I would never put 10A through these. So what i did was use all that empty space inside to convert it to a 4-wire tester by putting a good rechargeable lithium ion battery from an old cell phone + powerbank chip + a homemade LM317 100 mA constant current circuit inside, with a 2P connector in place of the 10A jack. Everything else still works off 9V, but I get the most use out of checking USB cables with the 4-wire-on-demand feature I added in conjunction with the 200 mV setting (multiply by 10 for milliohms). I don't know if anyone makes a small portable 4-wire tester like what I now have? I know this multimeter is a joke, but not everybody needs a big knife! A really nice meter for someone who can't afford much.
love how you have the safety knife compared to the Dundee blade :)
sagans segment intro really made me smile! Good kid!
Seeing Sagan made me nostalgic - I used to teach pre-school, which in the US is for 4-5 year-old children (kindergarten is reserved for 6 year-old). I love their curiosity about the world, which Sagan shows frequently - 'what are these?' 'what is this for?' etc. Fun teaching that age, before they've become too cool to ask questions and become bored with school.
Always include him in your videos , I love this kid!
Not even in kindergarten and he can handle the screwdriver like a pro! :D
I think I may have been like that as a kid judging by what I already knew by the age of five or even 4 for that matter some people say because at that time I was rewiring hundred twenty volt AC lamps yeah I was repairing lamps at 5 years old so yeah I think I got sick and Beat just Maybe Kinda sorta.
Plus 600 volts is considered as HIGH voltage in to US. the breathalizer might need alcohol to work.
I love how you don't talk down to Sagan. Wish more parents would treat their kids with respect. Kudos.
Hey Dave, did you not show us those beautiful postcards from my fellow colleague Tony / Toni from Deutschland, did you? :)
Loved the mailbag video with Sagan talking!!!
that CTT box don't never gets old, here from Portugal
I have a friend who lives near a Harbor Freight. I had them go in to the store every day for over a week, buy a sheet-rock bit from the jug at the counter, and get a free meter. So then I had a multi-meter to give to each kid in my ham radio class.
I've bought a nice Amprobe AM550 when I started in EE. Now some time later I needed some more multimeters and I'm on a really tight budget, so I've ordered two of those from ebay. They will do it and for the more precise jobs I'll just use the Amprobe one.
IIRC the blue "wire-wrap" on the transformer is the filament winding - an easy way to make the extra winding that can withstand being kept at high HV level.
I was thinking it was a form of degauss coil.... if you know what that is then you are an old fart 😃
+A. R. Jasso Of course i know what a degaussing coil is. There is no need for degaussing in a electrostatic deflected CRT with no shadow mask. The Mu-metal shielding around the tube takes care of the shielding of errant magnetic fields.
"Remember to keep children away." "...bugger that, I'm giving it to Sagan." Dying.
Actually I think Sagan would be better with a fluke meter once he's old enough to be responsible using it of course I would not trust that meter with if I had a son for his own protection and would have him a decent meter for full protection for inputs than all that because people make mistakes when they measure things that's why that production is supposed to be there if he were to blow up a meter she would learn Omar send it about proper testing protocol for example blowing the HRC fuse would let him know that poops I did something I should no not to do instead of having the meter blow up in his hands and possibly mean never able to test any circuit again due to a messed up hand or worse possibly be no longer among the living because of a cheap alternator scratch that multimeter Google you know The Giver of pain and sometimes laughter and other times just frustration LOL.
That scope is awesome!
Wow, they actually got a trimming pot inside of this one. On couple of these ICL7106 ripoff meters that I've bought in the local shopping mall because they costed less than the 9V battery inside they actually cut costs by replacing trimmer with just a regular resistor... And a bit of plastic cost by omitting the battery chamber and just randomly sticking the battery between PCB and case.
As others have said the unknown sensor is a PIR type device. The lack of fresnel will just mean the detection area will be very narrow, could be a people counter device.
I have one of those, this is the multimeter use on construction sites, where it is very likely to get damaged or stolen. If it got stolen or kicked off a building, don't even need to bother about finding it, and its so cheap nobody would bother stealing it, and if they did I wouldn't even care.
Oh man loved the mm instructions
I have maybe ten of these Harbor Freight multimeters, and I LOVE them.
I use them for doing assembly work primarily, and may need to ensure that 12 volts or 24 volts, or whatever is actually present. But may go ten or 20 minutes between uses.
These are the only multimeters I own which actually have an on-off switch So they get used quite a lot.
I have better multimeters which I grab when I need to actually need to measure something.
48:45: Its a Blaupunkt.
Like my first car stereo. I had the first Blaupunkt with digital tuner.
And they make alko-sensors altso. What a bobby dazzler!
Just love that small scope...
Sagan! What an awesome helper.
I Do not toss out cheap DMMs, Use as a DIY>panel meter< or DIY test box, has on /off switch so U can tap your power. -as them 1$ multi-meters make for good DIY custom solo-meter test box, just fix the range for the job u need check the calibration< & add buffer /shunt ..esc. - Also - when I was 8yro I did test the wall outlet with my dad,s analogue meter as most radios at that time , had HT of 400V
The Rossin wall mount maybe a wall alarm speaker for sounding an alarm tone to alert you of a fire or brake in.
Dave the super dad! Fun to see how quick your son is progressing,... Within a short time he really needs his one workstation, along Dave2