This high-power version of an audio oscillator produces a strong audible tone
using a piezoelectric transducer. All four gates existing in the 4093 lC are
used in this project to drive the transducer with a good audio signal.
The circuit can be used in alarms, toys, as a standalone project to teach
about oscillators specifically, orin experiments using continuous sounds in
the frequency range between 100 and 10,000 Hz.
The recommended piezoelectric transducer emits maximum output power
between 700 and 3,000 Hz, but it will also operate in other frequencies with
less power.
Power supply voltage range is between 5and 12 volts. Current requirements
depend upon the power supply voltage, ranging from 10 to 50 mA typically.
Pl adjusts the tone frequency. Cl can be altered within a large range of
values as indicated in the schematic diagram, shown in Figure l.
Components placement on a printed-circuit board is shown in Figurc 2.You
can also mounthe circuit using a solderless board for experimental applications.
Allthe components and the batteries (if used as powersupply) can be housed
in a small plastic box.
BZ can be replaced with a common piezoelectric tweeter. But, in this case,
you should open the tweeter and remove the small transformer from inside it.
Then the output of the circuit should be connected directly to the small piezoelectric transducer.
Parts List - High-Power Audio Oscillator
lOl - 40938 CMOS integrated circuit
BZ - Piezoelectric transducer
(Radio Shack 273-090 or equivalent)
P1 - 100,000 ohm potentiometer
Rl - 10,000 ohm, 114W,5% resistor
C1 - 1200 pF to 0.047 uF ceramic or metal film capacitor
No comments:
Post a Comment