Transformerless-annunciator


Posted on Dec 21, 2012    7719

This circuit does not require an output transformer or an output coupling capacitor; the annunciator can easily be turned on or off by a control input voltage driving a 10Mohm input resistor, R3. For a smaller acoustic output, replace output transistor Ql, with a 100ohm resistor,


Transformerless-annunciator
Click here to download the full size of the above Circuit.

while also raising the voice coil impedance to 100ohm, to prevent loading of the IC.




Leave Comment

characters left:

New Circuits

.

 



Top