IC 555 Tested Mini Projects

IC 555 as adjustable duty cycle flasher

This circuit of IC 555 as adjustable duty cycle flasher is unique. It uses the trick of charging the timing capacitor C1 through two different paths of resistors R2 and R3, via two independent diodes D1 and D2. Working When power supply is connected to the circuit (9V, PP3 battery) the timing capacitor C1 starts charging…

Filed Under: Bifocal Electronics

Simple OFF delay timer circuit using IC 555

As you may know, there are three types of timer circuits: ON delay timer, OFF delay timer and the PERIODIC timer. Here is the circuit of OFF delay timer using IC 555. Circuit diagram Working When supply is connected to the circuit keeping the push-to-on switch in OFF condition, the output of the IC remains…

Filed Under: Bifocal Electronics
IC555 mini projects

Practical circuit of touch timer using IC 555

It is an interesting application of IC 555. The trigger pin-2 of the IC is sensitive to human touch. This property is used in the circuit. Circuit diagram Working In this circuit when supply is connected, the output of the IC remains LOW and the relay remains deactivated. The timing capacitor C1 remains discharged into…

Filed Under: Bifocal Electronics

Pin Configuration & Function of IC 555 Have you checked our most popular mini projects using IC555? Simple mini projects for your school & college level project submission. Pin-1, GROUND: It is the GROUND PIN of the IC. The negative terminal of DC power supply or battery is connected to this pin. Here note that…

Filed Under: Bifocal Electronics

Security alarm using IC 555

We know that when pin-4 is connected to positive potential, the IC works in normal condition, but whenever, the pin-4 is connected to ground, it overrides all functions of the IC and the output of the IC remains LOW. This facility is used in the following circuit to design a simple security system. Circuit diagram…

Filed Under: Bifocal Electronics