555 timer radio

• Changes have been made to this instructable, these changes are denoted by asterisks ( * )

A single station 555 timer radio from a few simple and common parts. Switches between an oscillator and AM radio receiver. A few things I should warn you about before you get too excited...

1. This is a simple circuit I built by accident, it does not mean it is the best way to build it.
2. I'm still new to circuit mathematics so it have a few problems or calculations that could help find a better solution for this circuit.
3. It's currently a single station radio (I don't actually know the range because I think I live within a 1/4 mile of the station I'm receiving from)
4. It's really static-y and voices are a bit garbled (the first time it worked i thought it was just the capacitors discharging and having the trimmer resistor in between resistance values), I believe you can get it in a better quality with a few more electronics but i haven't tested that theory out.

If you can help me in any way, leave a comment and don't leave comments that don't actually help any other readers reading this instructable.

Also note: I do in fact know the pics are pretty low quality, I'm still getting used to my new camera.

Step 1 The parts you'll need

*3 resistors - *220 ohm, *100 ohm, *1 Megohm
*3 capacitors- 2 x .01 microFarad, *10pF ( .00001 microFarads = 10 picoFarads) You can use a 10 microFarad capacitor if you do not have a 10 picoFarad capacitor (you can get them in a value packs at Radio Shack)

• approx. 6 or more inches of single solid-strand wire (or an antenna)

1 LED (optional)
1 555 timer IC chip
*2 trimmer resistors or potentiometers- (It's ok if this isn't exact) 83 kilohm
*1 8 ohm speaker (not a 'beeper', a piezospeaker will work but it's not really worth it because it's very quiet)
1 9v battery and 9v battery connector (note: What I'm using is a 5v (wall) power supply from a different breadboard but a 9v will do just fine)

Comments

[apaterson1]

hi for your receiving capacitor you should use a variable on that should change stations

[naveen.sai451]

great work

[ASCAS]

In a NE555 chip i think you just need to change the capacitor to change the frequency. try adding a trimer cap. =)

[lxkarthi]

what is exact frequency of this radio? can u provide me a simple circuit for transmission also?

[MacDynamo]

As far as the exact frequency, I believe it gets station 440 on my radio, however, I don't think the frequency of the chip matters since I've tried changing out the resistors and it hasn't changed the stations yet. As for the transmission circuit, I don't have one really because when thought I could try that myself all I could find were multi-transistorized circuits with transformer coils transistors, so not only don't I know how to control those circuits well, but I'm also not sure how it would apply to this circuit. (And no placing the antenna on the output pin does not transmit any signal, most likely because it's far too weak and has no consistent frequency.)

[fd18]

The LED across the speaker contacts could cause "turbulence", in terms of resistance...maybe. Just assuming

[sur]

it would be better if u please tell us something about the working of the circuit.. like how the circuit works with signals n how triggering and threshold takes place?

[aliyevzaur1989]

How can i work?!
It doesen`t even have a coil?!  O_o

[mattccc]

is it am or fm

[shawntherobot]

it says on step 3 it AM but very crackly and 1 station

 

[qwertyboy]

this is pretty cool. hint: try using the macro setting on your camera (normally denounced by the flower setting) and make sure you have good light.

[MacDynamo]

Hey thanks for the help and support guys!

[8bitprodigy]

as far as changing stations, try swapping out one or more of the resistors with a potentiomenter (variable resistor) until you find which one controls it. have fun.

[brunoip]

good work !