4066 Quad Bilateral Switch

This circuit demonstrates the basic application of IC CD4066. Each of the four switches controls its corresponding input/output. By replacing the switches with wires of different length, the circuit can be turned into a water level indicator.

LM3915 Dot/Bar Display Driver

Vibration Meter

In this circuit, the LM3915 IC detects voltages that the piezo sensor creates when there is a vibration. Signal is measured via pin 5. The outputs that sink current drive 10 LEDs. The number of LEDs that are energized depends on the vibration intensity.

ULN2803A Darlington Transistor Arrays

The ULN2803 is useful for providing power to loads that cannot be handled directly by microcontrollers. Pins 1-8 are designed to receive low level signals. Pins 11-18 are the outputs. Put it simpy, It works exactly similar to transistor. Pin 1 drives pin 18, pin 2 drives pin 17, and so on. In this circuit, nine LEDS are interfaced with Arduino using ULN2803A IC. The digital I/O pins on the Arduino can only sink 40mA so that driving multiple LEDs is beyond its capabilities. The LEDs are powered by the 9V battery.

4060 14-Stage Ripple Carry Binary Counters

Row Of LEDs

Here, the CD4060 IC is configured to send signals to a row of LED lights. Each LED in a row is connected to the corresponding output pin of the IC. LED #1 is connected to pin 7 (Q3), LED #2 is connected to pin 5 (Q4), LED #3 is connected to pin 4 (Q5), and so on. Pin 12 (Reset) is connected to LOW for enabling the IC to function (oscillate). This demonstrates how the IC generates oscillations at its various outputs.

Keep The Output HIGH

This circuit uses the 4060 IC as a timer. Connect the pin 12 (RESET) to the positive pole of the battery and then connect to the negative terminal. The LED will illuminate after 5 seconds. The time delay period is determined by the 0.1 µF capacitor and the 1M resistor. The 1N4148 diode connects pin 7 (output) to pin 11 to block the oscillation. It keeps the output high until resetting.

4013 Dual D Flip-Flop

This circuit demonstrates the use of 4013 IC. Either the LED on pin 1 (Q) or the one on pin 2 (not-Q) lights up whenever the DATA input (pin 5) is connected either to a LOW voltage or to a HIGH voltage.The logic states of the outputs can only change when the CLOCK input (pin 3) is high at the clock edge. This follows the truth table of D flip-flop. For this purpose, the 555 timer is set-up to generate a low frequency clock signal (around 1HZ). A LED light is connected to pin 3 so that how the circuit responds to a change from LOW to HIGH can be seen easily. The set/reset inputs of the 4013 IC are connected to 0V.

4027 Dual JK Flip-Flop

Light Controlled Toggle Switch

4027 IC has four inputs (J, K, Set, Reset, and Clock) and two outputs (Q1 and not-Q). Here, a 4027 IC is designed in the toggle mode. The LED turns on or off and remain in that state whenever the resistance of the LDR changes. The 741 IC acts as a comparator. When light falls on LDR, Vin (pin 3) rises above or falls below Vref (pin 2) and the output changes polarity. The output is then sent to the clock input of the 4027 IC. According to the truth table, the output Q (pin 1) will toggle from one state to the other when both the J and K inputs are HIGH. Set (pin 7) and Reset (pin 4) are connected to the negative battery terminal. These pins are not dependent on the clock.

4047 Low Power Monostable/Astable Multivibrator

In this circuit, the IC 4047 operates on free-running mode. There are three outputs. A square-wave normal output is delivered through pin 10. Pin 11 is the inverse of pin 10. If pin 10 is high, pin 11 is low. The duty cycle will always be 50%. Output from pin 13 is twice as fast. The oscillation frequency is determined by the 39K resistor and the 1 µ F capacitor.