I am trying to acquire, preferably encapsulated, a miniature audio oscillator 0.8 ? 1khz, normally biased off but activated when the control voltage is removed It must be capable of driving a miniature speaker (via an integral amp if necessary). 9V battery is the preferred power source but not critical. Does anyone know where such a thing could be purchased? As I need a lot of them, I am not into making them myself.
Thanks in advance
Patrick
How many is 'a lot' ? How loud ? What level of control voltage ?
The electronics to do this would be pretty simple - parts cost a quid or two, depending on quantity and sound level.
Feel free to email me of you want to discuss a custom-made solution
Is the frequency important? There are several small sounder units that will make a noise ;-) when only DC is applied. Maplin KU56 at 1.69 is one, and will operate on voltages from 3-24.
Of course it would need a box and switching circuit to make it a power off alarm.
If you don't have any success with a ready made unit, I'll give you a quote provided it's not for thousands. ;-)
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