I've been trying to design my own wireless water level indicator(1 level) transmitting at low power as possible by my own design.

The idea is that a voltage divider bias via capacitor that on the circuit for Only a fixed time while water level indicator On. Thus reducing power consumption. The emitter follower setup is then fed to a colpitts oscillator. My idea is that transmitter should transmit at a frequency equal to 455 mhz or a frequency that have strength even at 10 meters and receiver should receive this frequency and turns on a buzzer. I still haven't made up the calculation of component values as I am pretty not sure about this circuit. I have only limited knowledge and I am confused about this project's practical efficiency and components available in the market. Also I've been thinking about replacing transistors with mosfet. Is there a better way to do this project or what can I do to tweak this circuit to make it practical.

 

hi 2001,
Welcome to AAC.
Have you considered buying a ready made TX RX pair.?
E
https://www.ebay.co.uk/itm/433-Mhz-...h=item3f9c5306c1:g:yrUAAOSwADpa1PcU:rk:2:pf:0

 

hi 2001,
Welcome to AAC.
Have you considered buying a ready made TX RX pair.?
E
https://www.ebay.co.uk/itm/433-Mhz-...h=item3f9c5306c1:g:yrUAAOSwADpa1PcU:rk:2:pf:0

My intention in making this project is not only the purpose but also knowing more about designing and gaining knowledge into the core.

 

Hi,

You need to use an ISM band to be legal.
If you detection is not critical, you can build your own but if not, you need to buy a system which will be reliable.

Well, to do this, it is necessary to have a transmitter which sends information to a receiver.

You have a transmitter, but in ISM band (like 433MHz in France), an homemade colpitts or other oscillator will be critical to realize. I suggest to you to use an FM modulator (to send buzzer tonality) build on a PLL (you can realize your own system) with an RF amplifier (PGA-103+ or other) to have a sufficient power (but be careful, ISM band authorized very low power).

Now, you have an RF signal ready to be demodulated. And it becomes more difficult. To decode properly this signal, and to be resistant to the interference, you need to have a good receiver, like superheterodyne receiver. You can found schematic on internet.

It's a great project. You can also found a lot of schematic of transmitters and receivers on internet, maybe more simple that my solution.
Joss

 

Here are ready made modules, you won't make them for less,!! and will have problems with homemade designs with tuning them to match.

China
..
https://www.electrodragon.com/product/433m-rf-wireless-module-a-pair-of-receiver-and-transmitter/