Hello everyone,
I am new here and I do not have much knowledge about electrical circuits. I needed your help with something I am interested to build. I want to build a wireless system which lets me know if a machine (for example a car or any other vehicle) is currently turned on or not. I think I can take some of the electricity from the electrical parts of the machine to make a transmitter. Now I want to know how I can use this to know if it is running over a long distance. For example I am thinking about a small system which will send a signal and on the other side once the signal is received it will tell me if the machine is on or not (for example an LED will be lit when the machine is running). Can you guys please help me with this? Like tell me what kind of circuit I can build to make this work?
Thank you .

 

You need to give some idea of what you mean by "long distance". Do you mean a few inches or millions of light years ?

Les.

 

You need to give some idea of what you mean by "long distance". Do you mean a few inches or millions of light years ?

Les.

uhm ranging from a few kilometres to around 50 kilometres?

 

If you used VHF or UHF frequencies you would have to have the antennas mounted high enough so the pathe between them was not blocked by the curvature of the earth. (Or any other obstructions such as buildings.) Also In most countries licence free item (Such as blue tooth and Wi Fi are not allowed to be used with more than a relativly low transmission power limit. There is also a limit on the gain of the transmitting antenna so the ERP limit is not exceeded. You may be able to use a licenced frequency but you would have to pay a licence fee. I do not know of any frequencies that you would be able to use below VHF as that part of the spectrum is full of broadcast stations etc. You cold proably do what you want using the cellular networks.

Les.

 

Maybe modify a home surveillance system accessible by any smart phone. Much of this depends on exactly what you wish to monitor and what you plan to spend on the project as well as your location. For example I can place a current or flow sensor device on my sump pump to tell me when it is running. Systems like this can also be web accessible so there really is no limit what can be done using wireless monitoring systems. Wireless web servers are very common.

Ron

 

Sounds like a job for a mobile phone text system, like on an intruder system,.

 

Thank you all, i will definitely look into ur suggestions