The power supply can range from 5 to 12 V, and the “on” time of each LED can be adjusted independently to a wide range of values. This device can be used as component of alarms, in warning systems, toys, games, or as an experiment to teach about astable multivibrators.
In this application, two gates perform as an astable multivibrator.
The astable frequency is given by Cl, C2, R1, R2, and R3. Both, R1 and R3 act on the produced signal and on the “on” time of each gate output.
C1 and C2 can be altered in a wide range of values according the intended application for the device.
A schematic diagram of the device is shown in Fig. 1.
Proper positioning of the polarized components (electrolytic capacitors and LEDs) should be observed when mounting.
IC1 - 4093 CMOS integrated circuit
LED1, LED2 - Dual-color or red and green common LEDs
R1, R3 - 1,000,000 Ω - potentiometers
R2, R4 - 10,000 Ω, 1/4 W, 5% resistors
R5, R6 - 1/4 W, 5% resistors (see text) for values according power-supply voltage
C1, C2 - 10 µF to 470 µF, 16 WVDC electrolytic capacitors (see text)
C3 -100 µF, 16 WVDC electrolytic capacitor
