Good video, but it still fails to explain a few important things: - In series circuits, current is constant, meaning that current is the exact same at any point in that series circuit. - Current is NOT less affected by magnetic fields than is voltage. However, if extra current is magnetically induced at one or more points in a series circuit, that same current will also flow everywhere else in the circuit. Because of this, the transmitter is 'aware' of the extra unwanted current and can thus instantly adjust the loop current to compensate. The same applies to changes in the resistance of the series circuit. This compensation would not be possible if the process signal were sent as a voltage. - The action of the transmitter is key to the success of the current loop. It can instantly adjust its series resistance as required to regulate the loop current to the desired value. It also monitors the loop current so that it can instantly compensate for errors and outside influencing factors. - Some current loops DO use 0-20mA. One of the advantages of using 4mA as the minimum normal value is, as the video states, to allow detection of open circuit and/or loop power supply failure. Another big reason is that always having at least the 4mA quiescent current in the loop circuit, is that this provides a small power source to operate the transmitter, as long as the transmitter is designed to never require more than 4mA. Without this quiescent current, there would need to be an additional power supply to operate the transmitter circuitry; this scenario is called "4 wire". When the transmitter is designed to operate on only the quiescent 4mA, then no additional power supply is required, and this is called "2 wire".
Yes, 2-wire transducer(sensor) save costs in practical industrial use. there is our 2-wire transducer:g-sensor.net/signal-conditioner/ac_current_transducer//2019/0110/380.html
for a long distance signal transmission, voltage has a drop,but current does not , thats why normally use current to transmit electric signals. As far as a voltage/current transducer(sensor) is concerned, the output signal adopts 4-20mA that's because 4-20mA is a safe signal,esp,in a coal mine,or explosive-proof sites, the spark energy caused by 4-20mA current is not enought to cause explosion. www.g-sensor.net
It is better to use currents not voltages according to what I explained. using 4mA as a minimum instead of something like 1ma is according to my thought due to the fact that 1ma is almost noise level and you cannot differ between if it is noise or a signal, while 4ma is obviously not noise. thanks
@@Thundertronics انا سالت السؤال بناءا ع انه من الاسئلة العامة الممكن تنسال في مقابلات العمل هندسة ميكاترونيكس/ قسم الصيانة حسب ما سمعت من مهندسين . اذا ممكن تفيدني باي مصدر معلومات عن الموضوع بكون مشكورة
![โรงเรียนห้ามรัก โดนจับได้ตาย...!! [เอิร์นไดเม่]](http://i.ytimg.com/vi/4u02Sbr556Q/mqdefault.jpg)
![Instrumentation engineering beginner course [01] - Introduction](/img/n.gif)
Good video, but it still fails to explain a few important things:
- In series circuits, current is constant, meaning that current is the exact same at any point in that series circuit.
- Current is NOT less affected by magnetic fields than is voltage. However, if extra current is magnetically induced at one or more points in a series circuit, that same current will also flow everywhere else in the circuit. Because of this, the transmitter is 'aware' of the extra unwanted current and can thus instantly adjust the loop current to compensate. The same applies to changes in the resistance of the series circuit. This compensation would not be possible if the process signal were sent as a voltage.
- The action of the transmitter is key to the success of the current loop. It can instantly adjust its series resistance as required to regulate the loop current to the desired value. It also monitors the loop current so that it can instantly compensate for errors and outside influencing factors.
- Some current loops DO use 0-20mA. One of the advantages of using 4mA as the minimum normal value is, as the video states, to allow detection of open circuit and/or loop power supply failure. Another big reason is that always having at least the 4mA quiescent current in the loop circuit, is that this provides a small power source to operate the transmitter, as long as the transmitter is designed to never require more than 4mA. Without this quiescent current, there would need to be an additional power supply to operate the transmitter circuitry; this scenario is called "4 wire". When the transmitter is designed to operate on only the quiescent 4mA, then no additional power supply is required, and this is called "2 wire".
Yes, 2-wire transducer(sensor) save costs in practical industrial use. there is our 2-wire transducer:g-sensor.net/signal-conditioner/ac_current_transducer//2019/0110/380.html
Outstanding video explanation, informative, and straight to the point . Thank you for sharing
thanks!
As a rule if thumb. I will use 0-10V within a cabinet. And always use current [4-20ma] for all field wiring or if it leaves the cabinet.
yes for field always current-based stuff.
for a long distance signal transmission, voltage has a drop,but current does not , thats why normally use current to transmit electric signals. As far as a voltage/current transducer(sensor) is concerned, the output signal adopts 4-20mA that's because 4-20mA is a safe signal,esp,in a coal mine,or explosive-proof sites, the spark energy caused by 4-20mA current is not enought to cause explosion.
www.g-sensor.net
thanks for your feedback
Really nice explanation! Very clear~
Glad it was helpful!
Really good video. thanks!
Question, Why we don't have use 1V as a minimum voltage, hence we can detect both minimum and open circuit, like 0 and 4 mA
It is better to use currents not voltages according to what I explained. using 4mA as a minimum instead of something like 1ma is according to my thought due to the fact that 1ma is almost noise level and you cannot differ between if it is noise or a signal, while 4ma is obviously not noise.
thanks
Good work👍
Video is so nice but we want this type of all videos in Telugu launguage
good, you dnt offer online training
كيف ممكن اعرف الحساسات اذا ما عليها مواصفات
ممكن تذكر لي اسم واحد أو موديله حتى أدلك. لكن لو فيه هارت بتقدر ببساطة عن طريق جهاز الهارت
@@Thundertronics انا سالت السؤال بناءا ع انه من الاسئلة العامة الممكن تنسال في مقابلات العمل هندسة ميكاترونيكس/ قسم الصيانة حسب ما سمعت من مهندسين . اذا ممكن تفيدني باي مصدر معلومات عن الموضوع بكون مشكورة
Thanks
ما هو Noise؟
النويز وشوشة غير مرغوب فيها في الإشارة
@@Thundertronics ما سببها؟ وكيف نحل مشكلة وجودها؟
@@MM-vi9kh النويز موجود في العالم لأن عالمنا ليس ديجيتال. تحلها حسب كل مجال
ليش ما تشرح العربي؟
لأن قناتي إنجليزية من البداية
Arabic version is
v nice
4 20
I see what you did there
what? :)
Yup