The recommended output transducer is an earphone or a piezoelectric transducer, but this can also be altered by using a powerful transistorized output stage to drive loudspeakers or tweeters.
Required power supply Voltage is in the range between 5 and 12 V. As the current draín ís very 1oW, you can also use battery to supply the unit.
A schematic diagram of Touch-Controlled Oscillator II ís shown in Fíg. 1.
Figure 1 – Schematic diagram of the Touch Controlled Oscillator
IC1 - 4093B CMOS integrated circuit
X1 - Piezoelectric transducer or crystal earphone, Radio Shack 273-073 or equivalent
R1 - 10,000 Ω, 1/4 W, 5% resistor
R2 - 100,000 Ω potentiometer
C1 - 0.022 pF metal ñlm or ceramic capacitor
C2 - 100 µF - 12 WVDC electrolytic capacitor
