From: rob@despammer.com   
      
   I built an alarm circuit from a book I bought called Make Electronics by   
   Charles Platt.   
      
   https://drive.google.com/file/d/1NxvKdZCqykuSjBvPVoWz_MEMhKYMMz9   
   /view?usp=sharing   
      
   The said circuit produces a siren type sound on a buzzer  so I added an   
   led through a resistor, a 10k pot and a LDR. I then connected the centre   
   pin of the 10k pot to pin 2 on the top IC555 shown on the schematic   
      
      
   Working  version of the circuit   
   https://drive.google.com/file/d/1NwYnNkljKLd7ORmZ16VYrtb7ZwCsvAn   
   /view?usp=sharing   
      
   As the said circuit was working as I wanted with the ldr and buzzer, I   
   built another of the same circuit.   
      
   On this 2nd circuit, the led goes off when I adjust the 10k pot, but the   
   sound does not. It does on the first circuit I built.   
      
   Thanks   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)