Wailing Siren

#3
No feedback yet on this circuit. I've tried umpteen configurations now with little success and replaced components in case they are 'duff'. I have taken a few photos of the transistors I am using just in case someone recognises the fact that they are not 100% correct. The base number is ok but their seems to be so many variations I really suspect that the transistors are to blame for my lack of success.
CLUTCHING AT STRAWS!
Any feedback would be most welcome.

Konrad :(
 

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#5
Thanks Fleck,
Will give this a try - meanwhile it doesn't solve the wailing siren circuit problem. Has anybody built this? Members don't be shy! Post your comments please.
Konrad:confused:
 
#6
Fleck, Can you advise what the link is to pin 6 on the first 555? It has to be either 2 or 3 but confirmation would be good. Thanks.

Konrad :confused:
 
#7
Hey Konrad, I took your advice and made a breadboard layout based on this circuit diagram. I haven't reviewed it 100% so there may be a mistake; if there is and you happen to spot it, please let me know so I can fix it A.S.A.P. I looked up the datasheets for the BC557 Transistors to ensure I put the wires in the right pins. The BC547 had already provided the BCE pins for me.


I also made a Microsoft word document that contains both the circuit diagram and the breadboard layout in a neat, one page, file that is ready to print. This file is availbe online and you can download that here.
 
#10
Justin I have built the circuit according to the layout above and it didn't work. You mentioned altering the circuit. Is this the altered version? I've just noticed the two capacitors at the bottom of the breadboard. You have them down as 10 micro Farads. The symbol is for a ceramic disc capacitor and this should read 10 nano Farads as their is no polarity given as per the schematic.

Konrad:eek:
 
#11
Justin I have built the circuit according to the layout above and it didn't work. You mentioned altering the circuit. Is this the altered version? I've just noticed the two capacitors at the bottom of the breadboard. You have them down as 10 micro Farads. The symbol is for a ceramic disc capacitor and this should read 10 nano Farads as their is no polarity given as per the schematic.

Konrad:eek:
My mistake on the nano measurements.

Here is the new layout,

The only thing that needed changing was those measurements, besides that, it should work. Everything is connected properly and I just double checked the transistors. It could just be that this circuit doesn't work in general, such as how the music box circuit that you built was very quiet, and remember how the schematic was wrong? The speaker needed to go back into Pin 5, not to ground. It could be possible that there is an error in this schematic as well.

Updated Microsoft Office Word Document.