12 volts not required

Using my prototype timer I felt that the piezo alarm volume was too low.  So since the prototype has the Piezo Loudenator kit installed:

http://wb9kzy.com/louden.htm

one way to make it louder is to increase the supply voltage.  I had been using a 9 volt battery but 12 volts should be even better.  Now instead of putting 10 Nimh cells in series or 8 regular alkaline AA cells in series I remembered that I had tiny 12 volt and 6 volt batteries.  I decided to use two of the 6 volt batteries (known as 4LR44) in series.  After looking at the 4LR44 batteries I realized that two of them are roughly the same size as an AA cell.  So I dug out a two AA cell holder with switch (I didn't have any single AA cell holders) - then I soldered a jumper wire on the unused AA cell holder and also soldered a 9V snap on the wires.  Instant 12 volts !

After connecting the snap to the timer, installing the 4LR44 batteries in the holder and turning the switch on it worked OK but wasn't any louder than the 9V battery !!  Why ?

Unfortunately the circuit board of the timer prototype is hard to see without taking the timer out of the case.  After removing the board I saw that the CD4007 chip wasn't installed in the Piezo Loudenator - I have no memory anymore :(   So the prototype was just outputting a 3 volt square wave instead of an 18 volt peak to peak square wave.

After installing the CD4007 chip the timer piezo really screams with 12 volts - in fact it's too loud so I reverted to the 9 volt battery.

That was a waste of time and materials !

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm