Electronics Education for Appliance and HVAC Technicians. More information at www.TechCircuit.org or visit our Facebook group at facebook.com/groups/746823709133603 . #ElectronicsForApplianceTechnicians
Great job, Sir! It is such a simple idea to teach schematics through a detailed walk-thru, yet I have not found another channel that follows your model in explaining schematics thru following the different scenarios especially using color coding. Straight to the point, no time wasting no verbal garbage. You simply hit the target 100%.
Terrific video! I don’t have a kilowatt meter to test my 5yr old GE microwave that powers on, lights up, turntable turns but no heat. All door switches tested good with my multimeter. Also I replaced the control board which didn’t solve the problem. I’d appreciate any assistance. Can I assume it’s the diode, magnetron or transformer? If so I’ll replace the microwave. Thank so much.
I have a GE microwave that powers on, the timer counts down, and turntable turns. However it doesn’t heat up. Could the problem be one of the door switches? I’d appreciate any help. Thank you very much.
If you don't hear it running, then it is likely a door switch. If it is going through all of the motions, it is likely the magnetron. In that case, I like to do current draw testing per this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-fqb_ib7Hslo.html
I replaced the Triac. Now my LED bulb flickers at off. Then I noticed it says non-dimmable. Ordered a dimmable one from the jungle site. Hope this fixes it so I don’t have to buy a $110 board.
I am a kitchen engineer in a big casino and commercial food equipment repair guy by trade. I love infinite switches as opposed to capillary tube thermostats. Much easier to replace, easier to test, more readily available and way less expensive. These should be in everything that doesn't need precision temperature control, of which few things do.
Dang!! Thanks man. I'm a Journeyman electrician that typically does commercial. I once got a job to a very old home where the handyman refused to install a fan because with the breaker off we still read 30V on the hot. I was miffed to. I understood that it was "ghost voltage" and not hazardous however I just couldn't explain it properly. Now I fully understand. I have since purchased a Loz meter. Thank you Sir.
Hello TTC, you say we can test alot of this with a Votage pen. Are you talking about one of those digital pen testers? Those read 5 to 10 volts if I rememeber correctly from my old Lab Classes. Good vid by the way.
Excellent breakdown of the switch mechanics. I just replaced the switch on my stove but wasn't sure if my old one was working properly or not. Stove is 10 years old and that's the only burner switch I ever use so makes sense it might be worn out but you can't see the inside of the switch if there's soot or carbonization or if maybe the thermal plates are worn.
Sir this is a nice video , and from the video i have learned, or clicked in my head, that when you use a load for the normal multimeter, you are in a way adding an impendence in parellel to the internal high impendence of the multimeter, in doing so you would have a low total impendence, since the impendence of the load is very much less than the multimeter. In short we could say you are creating a low impendence multimeter with one which dont have a low impendence setting.
thanks, the sentence is confusing, "sometimes....even have leakage current through a high resistance..." Length of wire make more resistance to electrical flow, right? How can something that "Resists" electricity flow "higher" than other things, allow leakage? Leakage occurs when something has Low resistance? V=ir. Should the sentence say, "sometimes...even have leakage current through a something that has very low resistance..."?
Your knowledge of the basics is so impressive, were there any particular books you read or classes you have taken to really help everything sink in. I often feel like an upside down pyramid, I have a lot of knowledge but it’s all been learned out of order and I have trouble tying it back to the basics.
Thank you. I've always contended that a strong exposure to electrical theory academics is required to just understand the basics. The basics are driven by that underlying theory. My background is in Electrical Engineering Technology and circuit design, but that's not necessary. There are plenty of videos on electrical theory (lots in my channel, btw), that you can avail yourself of. I'd say to continually learn a lot more than you think you'll need to, and a deep understanding of the basics will happen.
Steve, at around the 2:40 mark you show a measurement at neutral wrt ground that reads a nominal 120v. Would we have seen that reading if the nightlight wasn't plugged into the receptacle above? Great video as always. Thank you.
No you wouldn't have because there is some connection to Neutral at the breaker box, but not a very good one - through the high resistance of a loose connection. What "pulls" neutral toward L1 is the low resistance of the light bulb (as compared to that high upstream resistance on neutral). The resulting "voltage divider" favors a very low voltage drop between L1 and the outlet's Neutral slot.
This all makes sense, kind of. That said, do I really need to replace the entire board, or is there a fix for this? Or am I just going to have to do without that light? Personally, I do not care, but my wife is irritated that the light feature doesn't work.
Not all door switchs click, some two prong side by side on panasonic nn cf microwaves don't make clicking noise, use of multimeter you will still hear the beep for on and off.
Wow, just like you said, the same happened to my smart ass. I went to take off the bulb, was like "nah, I shouldn't need to power it off". Next second I see the bulb had already broken and by the time I went to turn it to remove it, the 2 wires touched... And you know the rest. My triac was also bad, and then I found your video haha. Thanks again!
This is a very helpful video, thanks. Two questions: 1) Do you have a suggested source for buying new switches? 2) Is the problem sometimes a mechanical problem with the latch mechanism? About 2), we've had the problem that the microwave turntable and heating turn on only if we tug slightly outward on the door. A few months back, I did check the electrical function of the switches, finding them fine, but I've not heard of anyone having to pull on the door to get the microwave to heat. (No error message, and the countdown display turns on and runs--it is just the turntable and heater that require pulling on the door.)
I'm curious: what design change could have protected these triacs when the bulb blows and shorts? Could an extra inductor/choke inline with the light accomplish this?
@@TheTechCircuit love the idea of a switch on the access cover for the bulb. Smart. But, what about an inline fuse? I notice that you call out the 20a Line Fuse as "slow-blow". I'd assume, then, that there are fuses which respond quicker to overcurrent. Is this a thing? Perhaps more complex, but could the board also potentially sense current and disable voltage to the triac after so many 0a readings? In other words, if the board sensed 0 amps after so many checks, voltage supply to the load would be removed.
@@garrybaker7656 Yes there are more quickly reacting fuses, but since there is still a delay, the current spike may dstill take out the semiconductor junction. About monitoring the current - certainly there are ways to do that and to disable the triac - and while the engineers are at it, throw an error message prompting a bulb change.
To my knowledge all electric ranges use the same type of switches. Not sure but maybe some high end commercial stoves might use different tech instead of pulse modulation. Perhaps variable voltage and current switches but that's not common in home ranges.
If you touch your multimeter leads together and the meter reads almost 0 ohms then yes. If it reads close to 3.5 ohms, the resistance is in the meter leads or connections rather than in the switch.
There was a circuit from 2008 on a mower engine that purposely allowed crossover leakage induction volts from a 5 turn wire onto an adjacent 7 turn wire, WITHOUT core, so as the in series volts is increased from 12 to over 100 volts. Was this brilliant, or just a cheap method of increasing a lower voltage. See photo of S1R9A9M9 triple wires assembly electromagnet on internet images. The LOWER only section of 13 turns had steel core. This was in reference to HIS (2) RU-vid videos that can still be seen. . (On old, worn out ignition cables, they spark across in the dark at night when you lift the hood on bad ignition cables.) He put this to use for his project in 2008. Please write back so I know you received my message. Is this type called capacitive voltage induction? My first test on this showed a neon bulb glowing with at least 90v, FROM ONLY THE 7 TURNS WIRING, not electrically connected to 5 turns.
New sub here…you nailed it showing the discoloration on the switch leads! New switch should be here tomorrow! We almost ordered a new one @ 160.$ out LG is only 10 years old! Thank you very much!👍🏻☮✌🏻
Thank you for the helpful info. I'm not an electrician, but am curious: why does a loose upstream neutral connection cause its voltage to float under load?
