Understanding How NTC & PTC Inrush Current Limiters Work
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- čas přidán 11. 07. 2024
- This video will hopefully give you a better understanding by method of demonstration, of how NTC & PTC inrush current limiters are designed to operate. NTC's are commonly found in power supply circuits, and also used to limit inrush current to power transformers and small motors. PTC's are used for over-current protection(replacing fuses), and also for monitoring rechargeable battery temperatures. If the battery gets too hot while charging, the circuit will be interrupted.
If you have any questions or comments, don't be afraid to ask!
Thank You!
Great video these things have always been confusing to me. You have the unique ability to take things that are complicated and make it simple and easy to understand. If only my other electronics teachers had this ability.
LOL. Thanks. I try to make all my videos VERY easy to understand.
Gee the first 60 sec cleared questions. Nice video.
Thank you for a very well done explanation of how these limiters work.I am looking forward to more videos.
Thank you. good information and demo.
Thanks for this video 😘
Great video!
Very clear description as well as experiment. 2 thumbs up!!
You're welcome! Be sure to rate thumbs up, share my channel with others, and look over my extensive video playlists for other great videos of interest to you. Thanks
Excellent demonstration ... Loved it,,,
Great to hear! Be sure to share. Thanks
That's neat that your self taught. That's how I learned, and your right, if your fascinated in electronics as I was and am its much easier to learn. When I was younger I found the navy's electronic training course book and read it like it was lord of the rings or something lol . My fascination is really with rf but its all good ..peace
Nice job on the video
Glad you enjoyed it
very nicely done till I watched you vid I was confused as to the differences of ptc and pptc
Great Video!
Thanks! Be sure to rate thumbs up, check out my other videos, and share.
Very well explained. Thank you
You're welcome Mike! Be sure to check out my wide range of videos and share. Thank you!
Very informational, thank you.
Glad it was helpful Kevin! Be sure to rate thumbs up, consider subscribing, and look over my extensive video playlists below for many other videos of interest to you. Taking one minute to share a link to my channel with others on social networking sites would be greatly appreciated. Thanks
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Hi good video well explained Thank you.
Glad you enjoyed it! I have many great videos on my channel, so be sure to look over my video playlists below for other videos of interest to you, and most importantly share my channel with many others. Thanks
czcams.com/users/electronicsnmoreplaylists
Thanks for this video! Any pointers on how to read a thermistor's label? Does "8L10 10002" mean it acts like a 10K resistor at room temperature?
PPTC's are quicker to cut the load, but slower to react. PPTC's react like a cliff, while a PTC will react like a slope. The PTC will be quicker to start limiting the current, but the PPTC will be quicker to cut the current to effectively zero. In this case, slow and steady does not win the race ;)
However, in many cases, the PTC is safer as it will spend less time delivering too much current compared to the PPTC... so you have a tough decision to make. It really comes down to the continuous resistance spec for your specific load needs.
Thank you professor.
You're welcome! Be sure to check out my other videos and share my channel with many others. Thank you
very useful
easy explaination
amardeep singh Glad you enjoyed it! Be sure to rate thumbs up and share. Thanks
very nice it helped me alot i teach inter level
Do you have a good and easy way to recognize the difference between P/NTC circuits and ceramic caps? sometimes they look really close specially the ones that are really high end and expensive ones..
Really help me thanks.
Glad to hear that!
Thank you very much I love you man
Glad you enjoyed it! Be sure to check out my extensive video playlists for other great videos of interest to you, rate thumbs up, and share my channel with others. Thanks
I will and thank you again
Question, can a ptc be over loaded and burn out?
If I have a 10A (12v) ptc, between 12v Battery and super capacitor. When capacitor is empty (2v or so) and I make a parallel connection from battery to capacitor, the inrush current is approx 100amps.
Will the ptc isolate it upon connection? Or will the rush be too fast and overload and burn out the ptc?
I appreciate your helpful tutorials. If you don't mind, where did you get your electronics training? Please continue your videos- I look forward to them.
Self taught. Reading and the internet. When I was very young(7-10), I always took everything electrical/electronic apart to see how things worked. I'm a very fast learner. Show me something once or twice, and I can do it very well, "IF" I am interested in it. :-) You have people that are experts in one field(Not me), but they know very little about anything else. I see this a lot with doctors. On the other hand you have a guy like me that is not an expert in one area, but very skilled, and highly knowledgeable in many different areas. You can never stop learning. It actually irritates me to not be able to do something. Do I make mistakes? Of course I do. I'm not perfect.
Thanks for watching!
electronicsNmore
Very well put.
electronicsNmore I thought quite highly of you before. Now I'm even more impressed!
I recently tried wiring a NTC in series with my fridge compressor in an attemp to limit inrush current on start. I measured the regular inrush current of the compressor, it was about 50A @ 127Vac. I wired a single 10Ohm NTC in series, and expected the inrush to drop about 5 times, following Ohm's Law (127Vac/10Ohm = 12.7A). However, the results were quite unexpected haha. The inrush current still measured around 48A @ 127Vac, a negligible drop, futhermore, for my surprise, the NTC literally exploded on start LOL. Somehow it still managed to keep functioning after the inrush. Steady state current is about 2A, way less than NTC max. steady current specified on datasheet of 5A.
You need to use what's shown in my other video below.
czcams.com/video/1MPW1dqulWw/video.html
hello thankyou for your video, I have noticed that some PTC's (used for a degauss coil in a tv/monitor) sometimes have 2 legs but also sometimes have 3 legs. what is the 3rd leg for?
bread bin I never saw one with 3 legs.
Question on the PTC, does that thermistor keep drawing a load while it's hot and opening the circuit or does it simply cut the flow of electrons while it's hot?
No. A very high level of resistance is reached, and the flow of current stops.
i think from ur video the ne used in CFL circuit on the tube filament terminals are NTC whcich allow the filament of of cfl get safe start,,am i right ????...s i found some of the CFLS where they hav labels like 75L, HL PR1 , SP MZ6 theristors n searched a lot about what they ment what is thier voltage temp limits bout couldnt find any so can u plz explain about it or sent me some link ...kindly waiting for reply,,,and do u know why old CFLs only hav those stuffs but not on new ones??
and what is the requited capacity of thermistors for CFLS
Great video. I actually have a loudspeaker with two of these. One of them has appeared to have overheated and burnt at the connection to the board. I cleaned up the socket and resoldered it, but I'd like to order some spares. Would you know where I could order these? Thanks
Ebay
another great video, very good information, I didn't know that they existed, great little device. I have a question, the situation is a large air conditioner comes on and the inrush current is so high it blows out the UPS and then the server. any idea what kind of device I could use in this situation thanks mk.
snaprollinpitts Check out the inrush limiting circuit I have on my channel.
thanks
It is there any chance to use this kind of circuit to power a" Commonly open side of a relay!! and when the power come up turn on a fan for temperature control and engine...or something of that kind?? Thanks in advance.
I do not understand what your looking to do. I have temperature control circuits in my video playlists. I suggest you check them out.
Thanks for watching!
electronicsNmore yup! I found your video showing how to use the temperature cut out switch... Thank you very much. your comment is greatly appreciated.
Obrigado!!!
Thanks for the information !
I got a 12v dc motor with output power: 3.4 watts rated speed : 170 rpm rated current: 0.9A
ISo for my case in order to prevent the current increase more than 0.9a when the load of motor increase,i just buy a ptc and it will solve the problem? Thanks a lot in advanced .
You can use a PTC, but I would just buy a PPTC(polyswitch). You can look at a chart and choose exactly what you need. Just make sure the operating current is what you need. Ebay sells them cheap.
I couldn't get the mechanism of thermal taped PTC on battery systems. If I'm not wrong, it rearranges the charging current on rechargeable batteries. But I have an old non rechargeable battery pack here and it has 2 serial soldered PTCs. They are thermal taped as you said. Btw the pack is really old maybe from 1980s, it has not any circuits on it, just wires and 2 thermal taped PTCs.
very nice it helped me alot i teach inter level Www
Glad you enjoyed the video!
thanks alot
Glad you enjoyed the video! I have a lot of excellent videos on my channel that cover many different subjects, so be sure to check out my extensive video playlists for other videos of interest to you, rate thumbs up, and share my channel with others. Thank You
Thank you nice jop
What is the character of Ptc relay in fridge
i e why not conduct again after cutoff when its cold
Got a new respect for the pptc, ptc ,ntc! Is it possible to build a soft start for a well pump with any of these???
I would make sure the capacitor for your pump is good.
@@electronicsNmore it is a small 120v submerged pump, it pulls like 7 amps peak, I want to be easy as possible on my inverter, I'm looking into a soft start, I found a chinease board bun unsure, it looks to have a relay on it also, maybe it latches the relay after voltage rises?? thanks, for all the great videos!
@@electronicsNmore I think it's a universal motor, like in a 120v drill, its a cheap pump, just over $120 or so, I have heard ppl running some off DC, but may not be the same pump..
thanks!
You're welcome!
Good video. I am thinking about getting an NTC thermistor and connect it in series with my cars radiator fan.
Every time the fan kicks in, there is a sudden high draw of current that drops the voltage for the rest of the car for a second. Once the fan speeds up, the current draw is less and everything is back to normal.
If I connect one of these in series to the fan motor, I'm hoping it will slowly increase the current going to the fan and allow the alternator time to compensate for it. Do you think this will work?
You mean in series.
Sounds like you have a bad ground on your vehicle, or a faulty voltage regulator.
Yes. My mistake. I mean in series!
Thanks for pointing that out. I'll correct it.
I don't think connecting it an parallel would have been a very good idea :D
The fan might work for a second or two, but would then be shunted by the thermistor blowing a fuse!
A faulty regulator seems more likely to be the issue. I imagine a bad ground would cause a higher resistance, thus drawing less current.
I think the thermistor in series with the fan may still be a good idea though. At the very least it would give the motor a softer, less sudden start.
I don't know how many amps a fan motor would typically draw though. I imagine it's taking about 10A on startup, and perhaps three or four running full speed.
I'm sure I'll figure something out though. Heck if I can design a circuit to convert separate amber turn signals into combined red US style turn signals I'm sure I can manage it hehe.
I'll get a few NTC thermistors to mess around with. At the very least it's something new to add to my electronics kit.
Hello could u tell me what value would be best to use in a 4.2 v dc max 35amp circuit I want it to trip at anything over 35amp
Since you are using that much current, use a PPTC(Poly Switch resettable fuse). Many different voltages and current ratings available. Looks for one with a trip current of 35A.
Thanks For Watching.
Got a few that I salvaged from old electronics but could not find data sheet how do I tell the voltage and power ratings
Need to look up the component #'s online.
Methode connected ntc &ptc (parallel or series) in electrical circuit thank you
I hv question please help me.
If there are 3 R namely potentiometer,thermistor,and resistor( it hs been arranged like that) and that circuit is series. What happen with the voltage potential passing thermistor if thermistor get hot ?
It depends if the thermistor is PTC or NTC
Which beat to use kn a Solid state relay and how do I choose the right one?
Any chance you can recommend a 2 amperes 2 Amperes PTC Inrush Current Limiter?? I have been trying to find one but every where I look they only have NTC... which is the opposite that what I really need..???
You can buy a 2A PPTC(resettable fuse) on Ebay.
Hi, quick question. It might be a stupid question, but is there a difference between NTCs with leads that are straight vs leads with a kink? Does the kink serve any purpose? Thanks in advance.
No difference.
Hi ,is this the same kind of thermistor used in power pack batteries for 12v
+arumugam samy
Battery packs use a thermistor. A thermistor's resistance value changes when the external temperatures rises or falls. A NTC/PTC inrush limiter relies on current flowing through the component to changer the resistance.
Hi thanks for your swift reply ,I find your info very useful , I f need to purchase any of such NTC for my battery pack ,Do you have any contact that I can buy from. ..Thanks
Wow man, For years I have been saving "What I thought to be a ceramic capacitors" would you please share the best way to know when is a cap or when is a PTC?? or NTC?? Thanks in advance.
NTC's & PTC's do resemble ceramic capacitors. You have to read the component to see what it is.
Measure the cold resistance with a multimeter. If you can measure above 10Ohms its an NTC, if on the other hand it reads nearly zero its a PTC. Although the circuit where they are can give you a hint.
Susana Godinho thank you so very much! I really appreciated your input are a true wealth to me!
in a real life scenario, aprox. how fast will let's say a NTC 5d-20 change from initial resistance to final resistance with 2A as final current in a current limiter configuration? Seconds, milliseconds? Minutes?
I'd say a few seconds based on the lower level of current. I have many great videos on my channel that cover a wide range of subjects, so be sure to look over my extensive video playlists for other videos of interest to you, and most importantly share my channel with many others.Thanks for watching Guillermo!
are these components applicable to use in frequency dividers for audio speakers sir...especially for tweeter speaker connections?
Never seen them used for that purpose.
@@electronicsNmore ok sir thank u very much...more power to ur channel...maybe i will try putting polyfuse or pptc on my tweeter speakers...
hi
how to check whether a ntc thermistor 5ohms 4ampere (sck 054) is good or bad. when I checked the resistance at 25 degree Celsius it was showing 4.1 ohms. when I heated it with a lighter it was showing 2.7 something. is that normal?? this thermistor is coming near the fuse of acer lcd monitor power supply board. please explain
You would need to refer to the data sheet for that NTC thermistor for the specs. They're all different.
is it possible to create your own circuit that will limit the current without using these devices? i just hate to spend more money buying those ptc fuse ...its just rubbish that we have to spend money to buy it...
It's much more work and money to do it another way.
👍
can NTC Thermistors be used in parallel ?
Yes. You would have 1/2 the resistance value if using the same rated NTC's.
hi sir good video .how the ptc connect in a circuit.across +and - pole.or series in + or minus line? it is damge by over current?any chart is avilable for suitable ptc selection.pramo
Pramo Ku They are non-polar. You connect them either way in series. There are charts available online. Do a Google search.
Thanks.
thanks
sir this is same as resetable fuse
A PTC is very similar to a PPTC the way they operate. This difference is how they are made.
Is there a way to limit ac inrush current without generating heat?
You can use an inductor for inrush limiting. :-)
No
hi, thnx for this intelligent information, can you please guide me with the PTC circuit used in hot glue gun, and do you hv any contacts who can supply me the ptc heaters on regular basis
On 1:05, you mention NTC's have lower resistance when cool. I thought that when the temperature increases, the resistance decreases?
Yes, as NTC temp rises, the resistance drops.
hey.. I need your help Brother... I have a dc motor.. Which has very thick windings so low resistance... Due to that inrush current is very high and my supply is 3.3amps...19.5v.....The motor jerks... Crazy untill it chacha some speed...NOW HOW TO USE ntg Or pta to overcome such problem
www.ametherm.com/blog/inrush-current/dc-motor-inrush-current/
thq
When you are showing a light getting brighter, it would be worth locking off the automatic exposure on your camera.
Yes, the camera causes problems. Thanks for watching Dave!
Anyone else here because their home ac blower motor stopped working.....Quoted 750 to replace the motor. This thermistor cost me 3 bucks on amazon....
Sounds like you had crooks quote you.
That’s motor and fam assembly on a 5 year old carrier installed
You kept referencing the PTC as an NTC. NTCs get more resistive as the warm, whereas PTCs get less resistive as they warm.
With NTC thermistors, resistance decreases as
temperature rises. An NTC is commonly used as a temperature sensor, or
in series with a circuit as an inrush current limiter.With PTC thermistors, resistance increases as temperature rises. PTC thermistors are commonly installed in series with a circuit, and used to protect against overcurrent conditions, as resettable fuses.
Great video!!