Function of AC Power Transducer: Does It Output 4-20mA Like a Power Analyzer?

What actually is the function of an AC power transducer? Reading from various sources, it acts the same that of a power analyzer. Am I correct to say that it converts 4-20mA signal?

Thank you very much.

Hi there Rem, can you give us a link to the site or datasheet for the particular device you are looking at ? And basic details of the application you want to use it for ?

a transducer usually converts one electrical unit to another. for example - current transducers - attach to a power analyzer to provide inductive coupling to measure current flowing in a conductor - without the power analyzer they are just a passive device - they are essentially a transformer. Frank is right however - we need to know what you are looking at - what type of transducer? hall effect? current probe? current shunt? current transformer? there are a lot of different types out there.

Hi Frank & Kevin! Here is a copy of the datasheet for the transducer. It's actually an enquiry from us and the enquirer intends to use it for a power plant. Am thinking of offering him a power systems quality analyzer instead. Thanks for all you share...

From a brief glance at the datasheet, I understand that the unit provides analogue ouptuts proportional to the input values for monitoring a range of measurements, and calculates power usage, power factor etc.
These ranges can be extended with voltage and current transformers.
Alarm functions can be set for all measured parameters.

The data can be read with analog or digital instruments, and can also be read through a digital link to a PC or other computer system. It appears that additional software would be needed to provide a recording function, though I expect compatible software would be readily available for this.

A computer link is also used to program various functions, but if a USB connection is used it, requires the unit to be disconnect during this process.

That's my brief summary of the unit. Whether it is suitable for a "Power Plant" would depend greatly on the size and complexity of the plant ! I would guess it would be useful with a moderate sized generator. But I don't have enough knowledge of power systems engineering to advise further.

But by all means post another question with any specific requests, but use tags like "power system management"

Its a glorified testmeter that takes measue ments on 3 phase or single phase using modbus commands with progammable interface so that you can set the upper limit and lower limit of your measurements that you require via USB interface attached to a computer interface It enables you to have data aquasition for further analisys via network or serial interface, in this possibly usb as well that is RS232 AND RS485


SEE BELOW FOR MORE EXPLANATIONS OF COMS PROTOCOLS

http://www.ti.com/lit/an/slla272b/slla272b.pdf


So if it wants current measure ments it sends out an approriate modbus command and then aquires current samples sending this information back to a pc network so that you can view instantanious current or voltage or phase difference

Simply picture this as a massive test meter with all measurements combined inside using a set cpu command sent via a bus to a transducer of some type but utilising ADC technics to aquire those measurements

Thats essentially what it does


Modbus was developed in 1979 for use with its programmable logic controllers (PLCs)


Modbus allows for communication between many (approximately 240) devices connected to the same network, for example a system that measures temperature and humidity and communicates the results to a computer. Modbus is often used to connect a supervisory computer with a remote terminal unit (RTU) in supervisory control and data acquisition (SCADA) systems.

Many of the data types are named from its use in driving relays: a single-bit physical output is called a coil, and a single-bit physical input is called a discrete input or a contact.

If you want to know more about Modbus see link below
http://en.wikipedia.org/wiki/Modbus


THEN AFTER YOUVE READ UP ON THIS YOU WILL SEE JUST HOW MANY AVENUES YOU CAN RE ROUTE WITH JUST THIS ALONE APPLYING THIS LATERRALY TO WHAT??

Yes mobile phone networks meaning instantaneous measurements data acquisition on the fly

Who says there' s no room for engineering and development then Better hurry up smapsung and get your act together and start giving us the information we need to develope otherwise Im going to design from someone else , na , na , nah nah , nah

LOL About bleedin time

this physical contact between wiper and strip creates the possibility of arcing.RC Helicopter.between the two as the wiper is moved. With most potentiometer circuits, the current is so low that wiper arcing is negligible, but it is a possibility to be considered. If the potentiometer is to be operated in an environment where combustible vapor or dust is present, this potential for arcing translates into a potential for an explosion!

I’m not quite sure what you aiming at Dan could you explain this further for us Obviously you’ve put this into context with some relevance to the above subject could you enhance on your explanation of how this fits in please ?? I understand that in given circumstances what you’ve stated is correct but exactly how does this fall into the above category forgive me If I’m missing something here perhaps I could learn something new that you have seen with reference to the above topic

Rc helicopters is an interesting topic however I cant see the similarity btw the above datasheet for industrial applications and a helicopter unless of course you plan to use this very ultra small scale ( Incredibly ridiculous ) to use a data recorder or monitoring battery voltages in which case this would not be suitable I think one might to determine this from the physical size and also the cat that this equipment is indeed aimed at large factories and more obviously single phase and 3 phase mains power

Unless of course your helicopter operates from Dc to ac converters and requires 3 phase for some unknown very peculiar reason to which you are possibly the first to produce for such tiny applications


You have read through the datasheet i take it and are aware of the fact that this doesn’t use potentiometers so the risk if explosion with dust or otherwise is reduced other than electronic component failure or components bursting into flames or possibly capacitors or a chip exploding which is inherent in any electronic apparatus no matter how many precautions you undertake If this is your point your making

This unit simply measures by using transducers and subsequently outs this data to adc control systems internally in this box of tricks later to be passed via RS232 or RS485 with speed up to 115200 baud, which is perfect for simple applications and serial bus interfacing addressing other transducers in a factory for example to gather data

The important factors in this are multi drop systems , Noisy enviroments , industrial environments where precise measurements are required Hope that explains this for you

See below for more explanation re this

RS-485, is a standard defining the electrical characteristics of drivers and receivers for use in balanced digital multipoint systems. The standard is published by the Telecommunications Industry Association/Electronic Industries Alliance (TIA/EIA). Digital communications networks implementing the EIA-485 standard can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear, multi-drop configuration. These characteristics make such networks useful in industrial environments and similar applications.

For wiring applications and typical topoligy see below

http://www.maximintegrated.com/images/appnotes/763/763Fig09.gif