your description of a schmitt trigger isn't very good. A schmitt trigger changes the switching thershhold voltage in the other direction of the output voltage whenever the output gets switched.. That prevents any signal which is close to the switching voltage from switching on and off rapidly due to noise or a small changing signal.
It's not entirely wrong either. I use one to trigger a mosfet with a photoresistor. Without it it's a great burn-your-house-down-at-sunset-or-sunrise timer.
Derek N. Eder yeah probably not totally correct there either but, you get the general idea. Amplify the shit out if the signal, threshold it to get a nicer blinkenlight and then do something to also get sound.
ElectroBOOM does not have eyebrows, he has *eyebrow*, singular and skookum as frig. He uses it in place of steel wool. I had hoped for a Big Clive reference to pliers of knowledge or at least use of unreasonable force..
That's the trouble with the Liberal Industrial Establishment, it takes jobs away from hard working Americans. Back in my day, we used to call a non-contact voltage tester an apprentice.
I know a former licensed electrician who tests voltage by putting wires in his mouth and seeing how it feels. I’m serious. I couldn’t make that up if I tried.
Thank you for the videos. Between you, MrPete222 and Abom79 and I now own a lathe and a Bridgeport. Neither of which I had ever used prior to starting watching your videos about a little over a year ago. I consider the 3 of you my experience, talent and curiosity. Keep up the great work and know you're effecting others with what you are doing. I'm adding to my plastics and woods hobby shop with a lot of machinist equipment and honing those skills.
The original 'voltstick' only use one FET and 2 AA's, the gate of the fet going to a wire in the tip next to the led, so it was an open gate, didn't even need a pushbutton, very little to go wrong. sensitivity adjustment was bu placing a finger close to the tip to attenuate the signal. The Schmidt trigger is not exactly a square wave, as the voltage rises it 'toggles' to on, as it falls it toggles to off, there's a bit of hysteresis in the system too.
Bad experiences (detection unreliability) with the original Fluke model. Acquired a Uni-Trend UT12A detector (via a colleague who's dad worked for Uni-Trend), and that's lasted years - VERY reliable, and acceptably sensitive (i.e. relatively immune from floating neutral false detection). Recently acquired the "new" gadget from Mustool - their MT812. Interesting in that this has a graded (LED bar-graph) response - sensitive enough to detect neutral return / low induced voltages (so useful for tracing "de-energised" cables), but also capable of discriminating between "live" and "induced voltages". Not enough experience to fully trust this for "last minute checking", but it seems as good as the old Uni-Trend for high(er) voltage detection. Any other "early adopters" out there for comments??
I am a 12 year licensed journeyman electrician. I have owned many of those fluke hot sticks, hands-down the best option for under 600v noncontact meters. That was a little difficult to keep up with but then again maybe that’s because I was driving while watching. Well, that and there’s a big difference between electrical work and electronics work. At any rate well done sir.
It flashes happily when near a charge. You should get an industrial design award for this. I haven't seen more civilized use of hot glue and cardboard in RU-vid.
Explanation wasn't totally wasted on me because I just bought one of these and I was motivated to know how it worked, but I wasn't happy to hear that when I stick it in the socket "I" am electro charged. My heart skips beats as it is, I don't want to BE a capacitor. :-/
Crystal S. interesting. I guess then, when our heart beats, the electricity has to go somewhere, and that "somewhere" is the capacitance in the rest of our body? Still scary. I've seen capacitors blow!
@2:25 just wanted to bring up a (sometimes forgotten) point here. Voltage dividers only work for things like microcontroller inputs/other high impedance situations/etc. You can't use them to drop the voltage to actually power anything that will draw any useful amount of current, since you need the current through the first resistor to be more or less equal to the current through the second resistor for the equation to be valid.
sure you can. I drive 12v solenoid valves off 24 volts all the time; two 12 volt marker bulbs in parallel wired in series with the coil. You can also use LEDs on high voltage with the right value resistor...
Those two scenarios your describing aren't resistor dividers, those are current limiting resistors. the lightbulbs limit the current in the coil, and the resistor limits the current through the LED. Your idea in the video about powering a 5v device off of a 9 volt battery won't work if the device needs more than a few milliamps.
Yup, what the other gentlemen here have said. Let's go through an example here: Say you've got a load that draws 1 amp at 12 V, but you've only got a 24V power supply. Should be easy, right? Just wire up two resistors of the same value in series (for simplicity sake, say 1K Ohm each), and attach the load at the middle point between the two resistors, and all is good, right? But do the math and you'll see that everything is not good! Before you attach the load, you'll have 24V/(2K ohm) = 12mA of current through both of the resistors. Attach the load, and suddenly you'll need to pull an additional 1 Amp through *only* the first resistor, which isn't going to happen if you keep that resistor value at 1K and the supply voltage at 24V (since V=IR, if you wanted to keep a 12V drop across the first resistor, you'd need to drop the resistance value down to ~12ohm - and get a resistor rated for 12W heehee!). If you know that the current draw will *always* be constant, then you could make it work by doing the proper math ahead of time. But if your current draw varies (such as with a motor with varying loads, a bunch of LEDs that you've got a dimmer attached to, etc), a resistive divider just won't work well for you. That's why (along with efficiency/heat concerns) voltage regulators are used when you're going to be actually powering something with a lower-than-supply voltage.
Rule of thumb is you want to pull no more than 1/10th of the current that goes through the whole divider on the center tap if you don't want to have to factor in the additional drop. Obviously that current shouldn't vary much.
One of those ticker testers saved me and my buddy's life at work one day. We were at Irving tissue in their switchgear room getting ready to add another section to the row of breaker racks. The Journeyman we were working under, along with a plant maintenance worker, disconnected the power and locked out the section we were to work on. Then we were given instructions to remove the side panels and remove the bolts holding the copper bus bars together to get ready for the new section. We got the covers all off and were getting the sockets and wrenches ready when I told my buddy "wait" and I pulled out my ticker pen just to make sure. That shit started ringing more than 12" away from the bars so I got out my meter and measured a full 600v across all phases. Turns out they cranked out the wrong breaker... Jeff was literally walking up to that thing with a wrench about to start working on those bus bars and I put my arm out to stop him when I said "wait". 1600amps 600v , about 30' from the exit, we would have been dead for sure!
@ 4:59, took me back to my high school days. We used to blow capacitors up in electronics class when the teacher would venture out of the room. Probably not the wisest thing to do. However, how many of us were wise in high school?
My friend in electric shop put a nail if each side of an outlet, laid his watch across them and powered it up. He didn’t understand why his watch wasn’t “shock proof” when it said it was. Not the brightest bulb...
How much R&D went into the proprietary shape of that home made tester you had there? I'm assuming there was some hands on experience involved in the process?
As an electrican hot sticks saved my life more then once. Even when the circuit is off I always always always hot stick it. I found out that several circuits that were off were still energized!
OK.... I HAVE USED THESE THINGS FOR YEARS THEN I WANT TO ADMIT, NEVER KNEW OR CARED HOW THEY WORKED. NOW WITH SECONDS LEFT (my analogy for my age) EVERYTHING IS NEW AGAIN! .....NICE PRESENTATION ....THANK YOU
So if we are the ones that are capacitively charged by the ticker why does the ticker still work if i ram it into the receptacle and walk away to find the breaker. I feel like im either missing something or theres more to it.
The detector is not using your body. It also has nothing to do with capacitance. The transistors are also not amplifying. The transistors are just digitizing the signal to make it either yes/no. www.jameco.com/Jameco/workshop/JamecoFavorites/non-contact-AC-voltage-detector.html
I always heard these things could go off on a magnet, I haven't had one in years, but I'm pretty sure I used to use one to test solenoid valves back in the day.
I have used many of those. Cheap, expensive, they all get broken in the same time. I would LOVE to use yours on the job. Maybe they wont disappear so frequently. That is great. Love it.
Are the 4 gold plated contacts on the Fluke meter acting as your capacitor plates? Also, If you're the small capacitor in the circuit, why was it working when you clearly left the Fluke meter in the socket and let go of it? Would that not have broken the circuit? Also, quality RU-vid buddy!
I've used these volt pens for well over 25 years as an industrial maintenance man and such, and know that they will detect AC voltage whether they are in my hand, or not. On numerous occasions, I have just laid the volt pen against a wire and walked away to start flipping circuit breakers to find the breaker to cut the circuit off, with 100% success. On several applications of really big wire (like '00' wire and stuff), I have used some 3M Super 33 (truth told, it might have been some cheap "Jap Wrap", but whatev...) to tape the volt pin directly to the hot wire, and it lights in a glorious fashion with no human (or non-human) contact or intervention at all. They may indeed rely on some leakage current from a capacitive circuit, but they most assuredly don't rely on you holding them - it's way more subtle than that. Tell ya what - make an outlet box on the end of an extension cord and turn the outlet "eye to the sky" up. Plug the dick end in, and stick your probe in the small hole (without need for apology of misdirection) of the receptacle, and walk away... FAR away... It will light up and chirp (if equipped to do so) no matter how far you wander. Volt pens don't NEED you, yo! They do their shit whether you're there or not. BTW, Santronics made the bomb diggity volt pens, but they got bought out a million years ago, and that sux.
When I worked as an electritian before I used to buy a load of these from a cheap off-brand manufacturer and keep a bunch on me. And when I encountered a carpenter or plummer who didn't know a lot about electricity I usually gave them a quick tutorial and gave them one of these "pens". I hope it saved some lives or at least made them check pipes or cables before cutting them.
Is the cardboard shape critical to the operation of your fabricobbled device? Or is it more an indicator of the original person who demanded this vijayo??
I had a Sperry stick for a couple of years. Got it because I needed one right away. It's gahbage. After the thing tried to kill me the 3rd time (said it was not live when it was) I bought a Fluke 1AC. That thing is great. It will tell me what side of an extension cord is the hot wire. The Sperry would sometimes go off when it came near a building in the rain, it would go off for any wire that was anywhere near something hot, then it would not go off when it was touching a bare live wire. Just hopeless. Should have bought the Fluke to start with.
Shit man, unlike others I don't want you to adopt me....I want you to teach me an intro class to electric engineering and machining. You manage to make things relatable for the layman better than anyone in youtube
I had a shit week at work. I was watching this while closing up the shop and when the shop-made tester appeared I laughed my ass off. Thanks for taking the gloom & doom out of my week.
As a patreon who tosses a single buck into the hat every month, all I demand is that you never cease being this awesome. And even if I tossed a thousand, that'd be all I'd demand. It's your fucking life and your fucking channel, you do as you please and it's up to us to enjoy the hell out of it!
A pH meter has two electrodes. When you dip them in the solution under test (an electrolyte) a voltage develops between them. That voltage is dependent on pH. Confuser then converts voltage into appropriate pH readout.
The electronics are simple (high impedance FET millivoltmeter is all you need - an "off the shelf" cheap meter works fine!). The electrodes are the costly component (though there are cheap ones via the usual Chinese suppliers). If you are looking for an accurate, linear (over a wide range) pH meter - then you're going to have to spend a little more (actually a LOT more), but as always you get what you pay for.
Can you do a follow up on phantom voltage? The breaker is off but the thing keeps beeping! Til you touch the box that is. Is it picking up something from wires laying over each other or is the user not grounded properly?
buillioncubes this! I had an instance where I was asked to help with figuring out why a dryer wasn't working. It was getting 240 V, even with the power to the house killed. It wouldn't start anything, and when I'd hit the start switch for the dryer, the voltage would vanish, but come right back once I let go.
It is most commonly induced voltage. Ive seen as high as 200 volts induced on a 347/600v system. The thing is there is no load so if you ground it nothing happens. But youll still read the voltage.
Capacitive coupling across the Mains switch. A common problem, especially when your Main Breaker only disconnects phase (not neutral). Most NCD's are so sensitive (high nanoampere sensitive), that they will register any static voltage.
I laughed the hell out loud when the home made version appeared! I can't come up with anything funnier than what's already in some of the comments about hands on testing etc.. I did wonder however what the conversation was with the better 3\4 on exactly HOW you wanted to build static electricity using her... And did she say no because you would have filmed it? You might should have mentioned that you are an expert at inserting blinding glare with perfect placement to obstruct view... You are a genius as far as I care so keep rocking! I love knowing what's inside and it's great that you break stuff so I don't have to.. Thanks.
Put some Scotch tape over your meter screen and get rid of that glare. As it sits, we have to trust that you know how to read numbers... I don't know if I trust you that much.
LOL ! I was eating breakfast and just about lost a mouthful of food when i first saw the shape of your tester! Thanks for the video AvE and a big THANK YOU for the laugh mate.
Did you just say electrons move in the one side and holes into the other!? I'm sure it was just a slip of the tongue, but in case it wasn't: Almost all capacitors use 2 or more metal conductors as their plates (yes, you do get such a thing as semiconductor capacitance, but that is a whole other can of worms and has nothing to do with how electrolytic, film, ceramic, polymer, tantalum, etc. capacitors work). Electrons move through the metal as a delocalized 'gas', without any holes being involved. Electron holes aren't simply the absence of an electron. Yes a hole is formed in semiconductors when an electron gets promoted into the conduction band, but those conduction electrons don't fall into the hole to 'move' it one space on, as current moves through. The moment a conduction electron falls into a hole, it's game over: The hole disappears and the electron becomes a normal bound electron again. Holes are their own quantum mechanical objects. They have their own masses, velocities, etc. which are all different from those of electrons in the same semiconductor.
DreamHazard; DreamHazard; Electricity is magic: My takeaway from first learning about it in grade school, not finding the explanations satisfactory, becoming annoyed enough to go study electrical engineering after highschool, still not really being OK with the whole thing, and currently, once again studying for an undergraduate degree, but this time in Physics. And it isn't even that I couldn't keep up and dropped out or something like that. The most frustrating part is that I have always gotten really good grades. I can't quite describe the feeling of graduating electrical engineering cum laude (which isn't that hard to do if I'm honest. The threshold is set waaay too low in my opinion, but I digress...), but still having no fucking clue what 'electricity' really is. For example: Do Cooper pairs 'travelling' through a superconductor also constitute electricity? Does the electron really have no size? As a simple example: To understand a simple circuit consisting of a DC voltage source, a switch and a lightbulb, you need to understand how (amongst many other things) the EM wave propagates once you close the switch; breaking out of the conductor and travelling along its surface, through the dielectric insulation around the cable. Just look at the "travelling through a dielectric" part: This is equivalent to light travelling through a transparent medium with some refractive index > 1. How is the light slowed down, without being otherwise affected? How is light generated when a charged particle (say, an electron) travels through the medium, at a speed faster than the phase velocity of light in that medium (basically, how does an electron going through the 'light-barrier' produce an 'optical boom'). Even when you finally grasp the answers given by the infinite path-integral approach of QED and applying relativity to it, it still leaves very fundamental questions lingering about; such as: HOW and WHY does a specific electron actually absorb or emit a photon? Is the probabilistic nature of absorbtion/emission the exact same mechanism as that which governs the photon's probabilistic travelling wave-function, which interacts with all possible atoms/particles and paths through the dielectric, or is it just modelled the same. Sorry for the long rant. You can probably tell it's an incredibly frustrating subject, which is also very close to my heart.
No. Lol Nikola Tesla (the person himslf) invented ac. Other have explained the rest.. Tesla motors has both edison and tesla rolling in their graves. "Tesla" branded car running on DC. Lol
Man, I'd pay a thousand bucks to attend your weekend inspirational seminar. *YOU* are a *CAPACITOR*. Your impedance is *SO HIGH* and you can capacitively couple to *ANYTHING!!!*...
I'm a electrichicken. Some say the oldest profession on earth is the.... You know what i mean...🙄😋 But that is not true, the oldest profession is electrichicken. And on day 1 God then separates the light from the dark and names the light “day” and the dark “night.” And the week before, we were installing the powercables......😀
So glad to see the pliers wrench make its debut on yer channel. I was hesitant to spend the dollhairs on mine but now i wouldn't give em up for anything
So if im the conductor...how is it they still work when duct taped to a wood broom handle? Or stick in an outlet and leave it to go flip some breakers till the chatter stops🤔
Ave, Buddy..! First person in a long time that's used the H word.. Yes, you said Holes. The absence of an electronic. You got me salivating like a young puppy again. Thank you, P.S. Let's see what school of thought you were raised in. Do holes move electron to electron, or do electrons move hole to hole. Absolutely wonderful, wonderful edumacation you're handing down to these Young Bucks.
I'm a fan of your familiarity with other youtubers. Also, you're incredibly well-read! It never seizes to amaze me how much shit you know! You hide your genius well.
