remote control using radio freq

[trigger]

I think I am wrong......
because those ICs I mentioned isn't operate in 1.5V......

And I think it is quite difficult to source for radio IC which operates in 1.5V for howbrew......

I am playing now with Toshiba TA2104 but its minimum voltage is 1.8V........ :-[

And MC3361 and MC3362 are not amp, they are IF front end where they are widely use for wireless intercom circuit for many years...

 

[keile]

i opened my father's wireless microphone receiver and it contained an TDA70** ic (sorry i forgot what number)... and it only runs on AAA size 1.5V battery.

 

[Hilo90mhz]

Did you check for a DC-DC converter inside that wireless MIC ? most circuits that run off a single cell use a small DC-DC converter to up the voltage to a more reasonable 3.3v or 5v.

Maxim IC makes some really simple dc-dc converter chips, with only a few external components needed. Ive used the MAX1674 before.

If you want to have a working prototype in a week or two, you should probably find a finished design instead of starting from scratch..

A 555 timer is good for about 1mhz max, depending on which model, I think most of them only go to 500khz..

Prebuilt transmitter/reciever modules are really a bargain.. and let you spend more time on the rest of the circuit.

Chester

 

[keile]

hello!

thanks Chester for some thought

yeah.. maybe there's some step-up ic inside .. coz the device also light a red LED to indicate if there's a signal (i know LED doesn't work on 1.5v).

it's around 10 days before our defense and i hope we can get the circuits fully working as soonest possible time.

wish us luck.. thanks everyone!

 

[MP1]

Here is how it can be done for LEDs:

http://users.cableaz.com/~cappels/dproj/ledpage/leddrv.htm

MP

 

[keile]

Greetings!

I wanted to take this time to thank everyone for sharing their time and knowledge to make this project possible. At last, we passed our design project. The only downside is that we had used infrared instead of radio frequency to give us more time to focus on the encoding and decoding section of the project.

Now that I have more time available, I'm planning to continue our original project. The time we spent on building the project had given me lots of knowledge on the electronics world.. heheh.. I really mean, I really learned a lot!

By the way, if you're interested here is the schematic for the transmitter and receiver section. Note that it uses infrared as a wireless links

View attachment 36167

 

[trigger]

Good!
IR is also a good solution.
For RF, it will take more time for you to troubleshoot and needed more equipment.....

But should be take great care if your circuit is used under bright light . Since the ambient light contain full spectrum of frequencies which may jam your IR signal or shorten the link distance.