Julian's Postbag: #71 - More Fun Electronics Stuff from China

[@tablatronix]

A cigar humidor is a humidity box for cigar storage.

[@TheAmmoniacal]

I can give a brief summary of TDS and EC. The meter only measures one thing, the electrical conductivity of the solution (in microsiemens / cm). All inorganic salts that dissolve in water will increase its conductivity, so there's a relationship between it's conductivity the total amount of dissolved solids (TDS). A simple formula is used to convert between the two, TDS (Total Dissolved Solids) and EC (Electrical Conductivity). Understanding how a water conductivity measurements works is a bit more complex, but I believe it's equivalent to measuring across two capacitors that are connected in series (Electrode --||--||-- Electrode). When an electric field is applied to the solution, ions migrate and accumulate at the electrode to cancel out the charge applied. The rate at which the charge is canceled is measured as the conductivity. The test signal used is often ~1-2 kHz sine wave at ~2 V p-p, but this can vary a lot -- if you get time you should put your scope on the TDS tester electrodes! (the third 'dimple' there is most likely the temperature sensor, as EC is temperature-dependent).

[@JulianIlett]

Thanks for the explanation - I'll scope the probes when I tear it down.

[@pileofstuff]

I'd bet money that the "mystery sensor" on the right of the 2 pins is actually the temperature sensor.

[@SurajGrewal]

so, we could probably use a multimeter with custom, fixed sized probes for the same. can't we?

[@TheAmmoniacal]

Suraj Grewal A regular multimeter most often use a DC voltage or current, that won't work. You can use an LCR meter instead. An EC measurement also depends on the surface area and geometry of your two probes, called the cell constant. In order to use an LCR for EC measurements you need to have a standard solution to compensate for this constant. Say you have a known standard of a KCl solution at 1460 microsiemens / cm, and your LCR meter reads 2250 microsiemens using custom probes 1 cm apart, the cell constant is -790

[@t.jtheron4790]

The key to a good conductivity meter is the measurement cell design. They try to minimise magnetic fields in the cell. Look at the design of a Metrohm conductivity cell.

[@ElGatoLoco698]

Humidor is used to store cigars. Keeps the humidity at the right level so the cigar stays fresh. I assume you would plug that round thing onto a cigar tube and use it as a portable humidor.

[@stan.rarick8556]

Put it into the humidor (box) to verify proper humidity levels

[@jlucasound]

@@stan.rarick8556 Agreed. It monitors humidity; it doesn't create it.

[@madrian_hello]

China stuff reviews are always fun to watch.

[@NicholasAarons]

Amazing Hall Of Kit Julian. The Reason why the hygrometers come up with Cigars is because a hygrometer can go inside a humidor which is where you would keep your cigars so they stay fresh with the right humidity hence why you would have a humidor i.e. A Cedar Wood Box to keep them in. I hope this helps. Keep up the great work. Nick.

[@t.jtheron4790]

Hi Firstly your channel is much appreciated. Watch virtually every video. Best way to test isolated power supplies is with a bidirectional digital current meter. If total isolation is not achieved between the power supply and measured current you get a fire due to earthing error across the shunt sensors. Test - and + currents. Testing the unit for isolation will be tricky. I stand under correction here but the input side is a square wave generator driving the primary side of a transformer, secondary side is followed by a diode bridge and capacitor. Only AC current can go through a transformer as the magnetic field needs to move to create current. One of four primary magnetic integral laws. Secondly ppm is a measure of dissolved MgCO3 and CaCO3 in water, commonly known as hardness. The micro S unit is 1/Resistance and commonly used in science. This quantity rises with less ions in water. Look up deionised water via reverse osmosis and ion exchange.

[@ljprep6250]

Julian, lay a piece of ribbon across the hole before putting the battery in. It pulls the battery out quite easily without the screwdriver marks. If you have one holder you use all the time, swapping batteries right and left, take a dremel to the holddown arms and shorten them to give it less hold. I do my own daily Chiwanese postbag openings, and your lists often end up as my own. Like Christmas every day, FOR A BUCK!

[@TheDutyPaid]

Fix the battery holder by putting in a battery, place in hot not boiling water, remove and enjoy. The hot water relaxes the wings but they still hold the battery.

[@lotsarats]

easier to just put a piece of ribbon behind the battery as you insert. pull it out like you do with most consumer electronics. fix the ribbon to the rear of the holder if you dont want it floating free.

[@turboslag]

That type of holder is designed to prevent calls falling out in portable devices. I just cut the clasps off for static and test use. A cable tie could then be used if required for any reason.

[@John_Ridley]

Big Clive soldering method at 4:20

[@JulianIlett]

Yes, all electronics enthusiasts must be able to hold solder in 3rd and 4th fingers and components between forefinger and thumb (and move them independently). It's the law :)

[@ohmhackman7365]

Here I thought I invented that

[@init_yeah]

Julian Ilett cant wait for your series hope its out asap

[@boblewis5558]

+Ohm Hackman ... Not unless you're Methuselah! Been around for decades if not centuries. Someone said earlier - pre-requisite skill for any electronics hobbyist (and/.or professional). :D

[@youpattube1]

TDS probably means Total Disolved Solids.

[@MyWillyboi]

Yes that's exactly what it means in this instance

[@jonjohnson102]

Or "Tear down stuff"

[@Roy_Tellason]

Those isolated converters came to my attention recently when I viewed a video of a fellow who had used three of them to give himself the ability to charge a 4S lithium pack. They do get rather warm, he said, when pushed to full output. And, 200mA is not much, but if you do a little searching they are available with somewhat higher current outputs.

[@retro80s22]

it's a cheapo nutrient wand very handy for measuring nutrients added to water in the hydroponics field so as not to tox your plants

[@Cavalier_Steve]

Just some information for you TDS stands for Total Dissolved Solids we use this type of meter to measure the conductivity of industrial steam boiler water. If you divide the TDS by 0.7 this will give you uS (Micro seamens) the less "rubbish" in the water the less conductivity there is. I hope this helps you. Steve.

[@robertcartier5088]

@13:50 You can easily fix the battery holder by shaving the plastic away with that utility knife, as long as you break off the end to make it sharp again! Another way, that I prefer, is to use the side of your soldering iron (on LOW temp) to melt the plastic a little... it has the added benefit of leaving a smooth edge that will not scratch your cells as they slide in or out. (The type of plastic those are made of appears to be type 2, which doesn't really stick to anything except itself, so don't worry too much about the iron getting any kind of permanent coating, or anything like that.)

[@StonyRC]

In case no-one has yet added a similar comment - the humidor reference relates to the storage of cigars. The temperature and humidity needs to be carefully maintained in order to keep them at their best and humidors are usually wooden cases or boxes with a humidity control function.

[@robertclark8351]

I've had good luck finding JST connectors, by searching for them as though I was going to use them on a quad copter or drone. They seem to be fairly common in that usage, and can bought in quantities of 10, inexpensively.

[@kvppvk]

Great stuff Julian. I've learnt a great deal from you over past year, and often have a chuckle at your side-comments. Best from Dorset.

[@JulianIlett]

Thanks Keith :)

[@RichardT2112]

Cigar humidor: place where you store your cigars, at a constant humidity. You therefore can buy humidity meters just for that purpose...

[@jimreviewsstuff]

Julian here's a idea to help with battery removal from those battery holders. Take a piece of ribbon and put it inside the battery holder with both ends hanging out of the holder. Then sit the battery in the middle of the ribbon. You will then be able to pull the battery out with the ribbon when your finished using it.

[@MkmeOrg]

On the eBay listings- I save the webpage to my local drive. That way I can search the folder and always have the exact details for the one purchased. Might work for you as well. Wish ebay would just stop wiping old purchases though. Cheers

[@jonvannatto]

MKme Lab The purchase listing is still there after 90 days it's harder to find them. To show them you need to select the year it was purchased in the drop down menu that sorts your purchases (on the right side iirc)

[@jdmitz]

TDS - Total Dissolved Solids EC - Electrical Conductivity - usually measured in micro mhos per centimeter. mhos is the inverse of ohms. Essentially the more TDS the higher the conductivity. You might want to play with distilled water and add salt to see how the conductivity works. Distilled water should have very low TDS and conductivity.

[@davidhoekje7842]

I assume TDS is total dissolved solids, and the light blue button is the temperature sensor. These are used with reverse osmosis units to verify that the membrane is working.

[@rialtho_the_magnificent]

High end cigars ( the ones you smoke) are supposed to be kept stored in certain humidity in a humidor so that "explains" the descriptoin for your round hygrometer

[@Kevin.Bowers]

Tip for removing batteries from battery holders: Use a small ziptie. push it between the battery and the holder, and it will follow around the battery and poke out the other side. then pull!

[@Edu_RJR]

Cigar humidors are for storage of cuban cigars

[@MobiusHorizons]

I would assume that refers to the color of the casing

[@cebruthius]

Strange, since my humidor is filled with longfillers, not one among them from Cuba

[@renxula]

That's frowned upon these days...

[@Mentorcase]

Cigarist!

[@cebruthius]

I'll take the opinion of these people www.welverdiendgenieten.nl/wp-content/uploads/2012/10/hajenus-sigaren.jpg

[@anks888]

Them dc-dc converters are good for generating floating supplies and negative supplies in audio applications if there noise is well filtered and the switching is above audio frequency

[@rich1051414]

No julian, it is for humidity control when storing your cigars. If the air is too dry, the cigars will dry out, if it's too humid, they will get moldy.

[@donaldfilbert4832]

Total Dissolved Solids (TDS): are the total amount of mobile charged ions, including minerals, salts or metals dissolved in a given volume of water, expressed in units of mg per unit volume of water (mg/L), also referred to as parts per million (ppm).

[@donaldfilbert4832]

No. Don Filbert - the Google guy - smile !! {:>)

[@Newsparklabs]

TDS=Total Dissolved Solids (minerals), and EC=Electrical Conductivity. Units of Conductivity are inverse ohms (Siemens) per centimeter.

[@An.Individual]

2:30 water hardness is measured in units of mg/l of CaCO3 in UK water industry. Hard is 200 to 350

[@robfenwitch7403]

A Humidor is the thing you keep your cigars in

[@turboslag]

Yeah, cigar fetishists need to keep their nasty things at a certain humidity!

[@TheJohn8765]

From your profile picture, it looks like you bring 'joy' to all those around you with your straight pipe exhaust. At least my cigars are enjoyed by myself and fellow enthusiasts alone.

[@turboslag]

TheJohn8765 Judging others is never a good idea, especially when you don't know them, in fact have never met them, and by using a thumbnail image as material on which to arrive at that judgment! I am actually a motorsport professional but have a diverse range of interests. So you reckon that your stinging foul habit doesn't affect others then?! Well, until you develop a terminal disease which affects your family and any friends you happen to have, and need the healthcare which is paid for by society, it doesn't! So, don't judge, lest you be judged by others.

[@chriselliott726]

@@turboslag Well, I for one have made a judgement about the kind of person you are ......

[@wolfgangmcq]

Regarding your struggles with the battery holder: have you tried a bit of ribbon or a strip of paper behind the battery? Then when it comes time to extract it you just pull the ribbon and it comes right out.

[@moificationable]

I was looking for a cheap isolated converted like the B0505S, thanks for pointing it out! I couldn't find a SIM1-0505 on ebay (for a sensible price) .. but this one seems to be rather similar, great!

[@ikkepic]

Humidity is very important for cigars. They have been kept at a minimum of 70%

[@DavidFowlerEngineer]

I purchased a PicKit3 on EBay recently. If did not work at all, and when I compared it to a good PicKit3 it was clearly a counterfeit. The package was missing the Microchip Logo. Your PicKit2 is also missing the logo. EBay stepped in and refunded my cost on the counterfeit unit. I was amazed that they went through all the trouble to put a large number of parts inside the unit. Other than the fact that it fails to function in any way, and the missing logo, it looked real. I am interested in whether yours work. For me, the Microchip software saw nothing connected, I did test with a good unit and all worked fine.

[@DavidFowlerEngineer]

The one you opened PCB looks different from mine. Yours might actually work.

[@built2last31]

looks like it measures dissolved solids in water you need to calibrate it in a test solution their used in growing pot when growing using hydroponics or to measure water hardness

[@beargun42]

The solder joints on the pickit 2's header seem a bit dry. The third "pin" on the water meter is probably the temperature sensor.

[@iLive2Ride76]

I really like this kind of videos with lots of China stuff 😀. Looking forward to the tear down of the tds meter because I'm using the exact one you bought. I'm using it in my aquariums. Mostly where I have my shrimps but also in fish tanks. BUT it doesn't measure water hardness. Although hard water will have impact on the result.

[@44kebeck]

In the boating world I use a TDS meter to see if my RO watermaker has indeed removed the salt but the taste test works just as well.

[@Inquire98]

"Thank You", thank you very much... I buy electronic grab bags, but I'd like to know, how to identify an electronic part, when NO nomenclature is available, or part number is visible 😐

[@BIBIwood]

For the USB buck converter you should check with your USB doctor what the voltage voltage is under load. I bought several models, most of them are outside the USB specs. You should also buy some silicon wires, they are nice to work with.

[@JulianIlett]

I just blew one of them up :(

[@maicod]

+bibiwood I have two, one rated 600 mA and one rated 1200 mA but both 'suck' and can only keep around 5V with loads of less than 100 mA

[@woodlandor]

In the weird water tester probe part. The "sensor" is a thermocouple which just measures temperature.

[@reeseyme9613]

just wrap a strip of double layer paper with both ends sticking out at the positive terminal so you can easily lift the battery out by pulling the ends of the paper.

[@MartinPHE]

Total Dissolved Solids. Guessing the EC is Electrical conductivity. Used these meters all the time in the field though we used Hach I think ours was about $200.00 each. To use properly you stir with it

[@taunteratwill1787]

"Presumably tinned copper"? :-) In your dreams maybe how about aluminum?

[@DaffyDaffyDaffy33322]

Could you use two of those DC isolators to make a bipolar power supply? Connect the inputs up in parallel and connect the +out to the -out of the other.

[@MobiusHorizons]

It would be interesting to power it up, and check the voltage difference between the input ground and the output -. If it is floating, you should be able to manipulated the voltage by touching the output, or connecting it to the input.

[@maicod]

maybe the sensor on the water quality meter is an LED and light-sensitive component in one that measures visual clarity of the water ?

[@PriorUniform721]

To keep a copy of listings you could print to PDF or maybe use Evernote.

[@PhaQ2]

A humidor is a box to keep cigars from drying out or moldering.

[@davepedu5896]

Hey Julian, what are the advantages and disadvantages of using one of those DC-DC convertors over a linear regulator? All I can come up with is price and the isolation difference you mentioned?

[@llsdigitek]

Lots of good tips here, thanks, I've ordered a few products.. THANKS! Lloyd

You can put a piece of fabric under the AA and then use that to pull it out.

[@SolarSteve]

So you should be able to use those isolated DC-DC converters with your MPPT solar controller, right? To isolate the N channel mosfet?

[@PhilXavierSierraJones]

"No Commercial Value" is often used to prevent customs rejection.

[@Bob_Burton]

I don't understand how items disappear so quickly from your Ebay purchases list. The list defaults to the last 60 days but I can select the whole of 2016, 2015 and 2014 Do you see something different ?

[@agarceran]

I think he makes a lot of orders, there might be a maximum number on that list and Julian is pushing them out of it with new ones.

[@pfeerick]

No, same here... defaults to the last 60 days, but you can pick all of 2016, 2015 and 2014 as well. Or recover the purchased item link from email ;)

[@JulianIlett]

They're still in my purchase history, but the seller is no longer selling the item, so the link would be useless. That's what I should have said.

[@Bob_Burton]

Thanks Julian. That makes more sense and I have had that problem when wanting to order more of a previously purchased item.

[@pfeerick]

Ah ha! Yes, that makes perfect sense now... thanks Julian! :D And like UKHeliBob, I have suffered from that same syndrome.... where you have bought your sample(s) (or have run out), and want more, and they don't stock them anymore! :(

[@cri8tor]

Hi Julian. Watched a video of a DIY MP3, bluetooth, speaker build. The B0505S was used between the power switch and the bluethoot module. Can't figure out why. Do you have any idea why a B0505S would be used in this application? Cheers

[@samuelashdown7994]

The Hygrometers are for cigar humidors i'd guess. For people who like to know how moist their cancers gonna be

[@guitarplayer1071]

tasty, tasty cancer.

[@TheJohn8765]

If you spend a few hundred dollars on cigars, you want to keep them at 70% humidity and below 75 degrees. Everything will kill you eventually, mate. The occasional cigar won't hasten the end any quicker than anything else.

[@domino52o26]

And add in the possibility any of us could bite the dust at any moment for any number of reasons, it's mostly pointless to fret over things that may affect your life possibly, at some point, somewhere along the line.

[@rich1051414]

Too humid and cigars will mold and burn too slow. Too dry and cigars will dry out and be harsh and burn too fast. 60-75% humidity is ideal.

[@DogRox]

I can't wait till you start working with the pic programmer. I haven't worked with the pic chips since that last time talk about that LOGIC program for the MLab IDE I did get that program by the way, thnx :-) my first micro controller project I ever did was with a 12F683 pic for a simple 5 LED scanner. :-) that was a long time ago. I just haven't played with it for a long time now. I've been working with AVR mostly. I want to get back into learning more Assembly Language for Pics. I have the Pickit 3 not the 2, but I'm definitely going to be glued to your videos then! :-)

[@JulianIlett]

Excellent! I just remember writing short programs to flash a LED (in lots of different ways) being great fun and challenging too. I also want to try driving a string of WS2812 LEDs with the PIC.

[@DogRox]

Julian Ilett looking forward to that!! :-) keep up the good work! :-)

[@TheUnnamedGent]

Do you know how those dc-dc isolated thingies work? Can you put the input in series with the output to make 10V? Or use two of them to make 10V?

[@JulianIlett]

Cool idea - a voltage doubler

[@TheUnnamedGent]

Do you think they have a transformer in them? If so it must be tiny with the inverter and rectifier in there too. Or is there some other way it could work?

[@JulianIlett]

The only other way would be a small motor and generator!

[@raykent3211]

Nope... the dc de-coupling could be done using two capacitors. Either method involves using the dc input to power a high frequency oscillator (probably in the MHz or gHz region for this size), transfer of energy without dc electrical conductivity and recuperation of the energy, probably with a bridge recifier and smoothing capacitor. At low frequencies the de-coupling is best done by magnetic transfer (coils of wire) but at very high frequencies capacitive coupling gets more efficient, more compact and cheaper. So I bet you a bag of crisps that them thingies don't have coils of wire in 'em. btw, if you win you'll have to come to Brittany to claim your bag of crisps, cos Theresa may ban me from re-entering the UK on grounds of associating with foreigners...

[@TheProCactus]

Would a Hall-Effect device detect a working coil ? Surely they are not isolated and are tiny switchmode devices. Therefore they need a coil ?

[@shmuelnaarai677]

Great stuff Julian! I need your help in fixing a powertool battery pack. 18.5v output x 5 cells 18650. The charger module is dead. What would you recommend as replacement board. Thanks & Regards. Sham.

[@normanparker2103]

Try putting a piece of Sellotape round your battery and you can put them out quite easily

[@lmorrison17]

I bought some of those usb boost converters and they voltage dropped horribly under load and they do not work for apple devices without tedious modification.

[@Polite_Cat]

personally i dont think you have to do all that work finding links and search strings.. its pretty much common sense when you show us the ebay page, finding almost all of these parts are easy if you type in a few words from the title of the item. unless its a rare or unusual item, there will usually be lots of sellers.

[@m3chanist]

Deep thought came up with 42, the tedious@EC says 297. To read the lcd or not to read..What is the question?

[@seth4413]

Hello Julian. Do you just get these random post bags as part of soe subscription or specifically buy the items? Would be fun if there is a subscription that you could order and get rand0o things. Take Care

[@robh1908]

I miss Julian's daily videos. Ah the good old days. I think it's because he has a very soothing voice and not back of the neck hair raising like Dave. Now on the other hand all Clive is doing these days is led's. Keep up the good work Julian.

[@JulianIlett]

Thanks - your comment is much appreciated. I'm going to make videos more frequently for a while.

[@JulianIlett]

Just editing another video right now :)

[@fibrodad1354]

is there such a thing as a power bank with variable voltage on it. i am making some usb to power adapter leads so i can run cameras and game handhelds etc. from 1,5v to 9v typically. best way of doing it.. hnx

[@jamest.5001]

I was wondering witch is easier to program and use. a arduino ( or clone) or a pic chip? I don't really know anything really about either. but a lot more can be done with an arduino. I'm just mostly interested in a high power DC boost circuit. that can regulate its output. can a pic do that . so I need 2 pwm outputs.and a input for regulation. but I'm probably missing something. witch chip would work?

[@Tom5TomEntertainment]

Where did you get your green grid work surface? I'd like to get one myself

[@Authoratah]

can you test the Riddex pest repellent? I bought 2 units off of ebay and of course they are fake, but worse than that....they are just blinking leds with no components that will sent any sort of frequency pulse to repel pests.

[@radius.indrawan]

please excuse my newbie question, knowing that MORNSUN B0505S module is isolated, does that mean i could put two of it in series to get 10v output from one 5v input supply?

[@MrBrymstond]

Can we wire these isolated converters so we can get past 200mAh? Like 5x200mAh= 1a?

[@robertheal5137]

microsiemens. A siemen is the reciprocal of an ohm

[@Anvilshock]

A Siemens*. The trailing s is part of the name, not a plural-s.

[@MyWillyboi]

Julian TDS is (Total Dissolved Solids) , EC I'm not so sure about! Cheers mate

[@cri8tor]

Recently purchased one of those DC-DC modules (B05058-W). Saw it used in "portable mini speaker" build, but don't know what it's function would be in a mini speaker set. Do you have any idea? Thank you so much for the thorough reviews. Cheers m8

[@jaywenden1939]

ms/ cm is testing mols per cm cubed i think, but correct me if im wrong

[@douro20]

If that is really a UL Recognised Component as the thing indicates, it HAS to be isolated as they say.

[@nor4277]

. Are those full Bridge rectifiers

[@retro80s22]

cut the wings off the battery holder with snips I had to do it with all my 18650 holders

[@Ronaldk4getstuff]

hello julian I have a question I made a small solar generator and have a 12v 14ah battery tender battery and I have made a battery from 18650's it is 10s X 3p 11.8 v I think can I connect them to increase my capacity of my 12v solar generator ? or should I make my diy battery 14.? v your thoughts on the project

[@stan.rarick8556]

I print the eBay page to PDF at time of purchase to preserve history

[@iceberg789]

any idea if those little 5V boost converters can be tweaked to give o/p of 3.3V ? i searched for the smd ic part online for datasheet, but nothing really comes up.

[@drkastenbrot]

Just buy a 3.3v one, that chip is fixed to 5v

[@iceberg789]

dont think there is any available that goes from one AA/0.9V to 3.3V

[@magnets1000]

There are, just search on aliexpress for "3.3v boost"

[@-yeme-]

you can get tiny boost converters which cover that voltage range, theyre called "Mini DC 0.8-3.3V to DC 3.3V Step Up Boost Power Module For Arduino Breadboard" on ebay uk

[@iceberg789]

right, thanks. found some, but those are expensive compared to 5V ones, each of those costs like 5-6 times of the 5V ones.

[@youpattube1]

And EC probably means Electrical Conductivity.

[@ThanerdNet]

youpattube1 confirmed. And uS/cm means micro Siemens per centimeter. Conductivity of a liquid is greatly impacted by temperature. In Pharma industry, we use that as a first indicator of purity of rinse water used to clean parts in contact with product. Norm is to be below 1.1uS/cm at 25C

[@Barrybados]

Julian setting up is grow room lol .

[@tianxizheng6647]

What are those wire strippers?

[@pdrg]

Cable is unlikley to be tinned copper, maybe aluminium or steel?

[@steubens7]

what's in the last memory location? I have no idea of anything to search for or context :x

[@JulianIlett]

It's a calibration value for the internal clock source. So every PIC12F675 is factory calibrated. But you have to load the calibration value into the OSCCAL register as part of your program.

[@larbond]

Your first meter has the buzzer down at the 5 o'clock position

[@justanothercubeguy]

Is the output of the 5v dc-dc converter stabilized? I accidently bought an other model that isnt.

[@daijoubu4529]

For those wondering the same, no it's not regulated, it also needs a minimum of 10% load or it goes out of specs

[@tyttuut]

I would love to see a PIC tutorial, particularly on coding in C for PIC 8 bit micros.

[@JulianIlett]

I'll be using assembly language.

[@1pjodan]

I love the sellers that are tax dodgers, and Julians comments about the values. It's not the tax so much I hate but the handling fee, I'm not asking anyone to handle it.

[@RoboticNerd]

What is the best component tester like the one you have for around $20? Is there such a device for that cheap?

[@-yeme-]

there are a few types on ebay and you can get them for around half that price. I think its mostly the display thats different for the various types. newer versions give you little diagrams, older models just show numerical parameters. the only criticism I have of mine is that its not very accurate when measuring small capacitors (

[@RoboticNerd]

0yeme0 Thanks, I just want one that can reliably tell the difference between a different types of transistors, and between transistors and SCRs.

[@geosplayground663]

can i use 3.3 volts here?

[@madmaniaq]

Awesome videos! Love it when these pop up on my smartphone. Question; what wire stripper do you use? Does it use the right thickness automatically?

[@reggiebacci]

Weicon wire stripper No. 5 - I asked him in a previous video ages ago. And yes automatic strippers like that usually self-adjust.

[@madmaniaq]

Thanks!

[@cmj20002]

I think it is Total Desolved Solids in the water.

[@riancurrie]

If you think those DC to DC converters are small Google this one from Texas Instruments: LMZ21700SILT

[@ww321]

TDs is total dissolved solids

[@ww321]

EC is electrical conductivity

[@jonnywaselectric]

KFC = Kentucky Fried Chicken

[@ww321]

Exactly ! :)

[@ElGatoLoco698]

In my previous job, I found out the hard way that Customs and border protection couldn't seem to grasp the concept of when someone purchases something and it doesn't work that a warranty replacement is sent. Sometimes that warranty replacement required us to send it out of country. That means the value of the item sent is $0 because it was already paid for and the item sent is only a replacement. I argued with a CPB agent for an hour one day over this. They are the most robotic and hard headed trashy people around. They are everything wrong with the United States. Needless to say, I found out that by putting one cent on the value, it would save a headache by the morons who work at CPB. Why? I don't know.

[@MrBrymstond]

You are rather addicting my friend!