Heart Shaped Serial LED Flasher using 4017 and 555 IC

This circuit uses the 555 IC and 4017 IC to flash the LED's one by one placed in shape of a Heart shaped , hence named LED flasher circuit. The 4017 is a decade counter which flashes the LED's one by one depending upon the clock signal received by it , here 555 produces clock signal and thus drives the 4017 IC to produce output at its pins. The output LED's can be easily connected in a Heart Shape in order to Make a nice flashing Heart effect.This...

Read More

Reaction Timer Game with 7 Segment

This is a game for two players. Player 1 presses the START button. This resets the 4026 counter chip and starts the 555 oscillator. The 555 produces 10 pulses per second and these are counted by the 4026 chip and displayed on the 7-Segment display. The second player is required to press the STOP button. This freezes the display by activating the Clock Inhibit line of the 4026 (pin 2). Two time-delay circuits are included. The first activates the...

Read More

Electronic Cricket Match Game using 555 IC and Decade Counter 4017

The Electronic Cricket Match game is presented below, the circuit has 8 LED which represent  various states in a cricket game - 2 runs ,six ,bowled etc. When the Push Switch S1 is pressed momentarily, the Astable operates and all the LEDs run very fast sequentially. When S1 is released, any one of the LED stands lit which indicates the status of the match. For example, if LED D7 remains lit, it indicates Sixer and if LED 8 remains lit,...

Read More

555 IC Tester Circuit

This simple 555 IC testing-circuit tests your entire 555 timer IC, so before using your IC check immediately that your IC is good or bad by checking it. This can be done by checking the IC that is it is oscillating or not. Or you can use this circuit in some other circuits also to troubleshoot the proper working of 555 IC. First of all insert the IC in socket very carefully so that no pin of 555 timer get damage. Now to see the result, switch...

Read More

Drakness Detector using 741 opamp IC

The circuit below is darkness detector that is it automatically turns on the LED when LDR senses no light. LDR is the light dependent resistor when exposed to darkness, a LDR has a tremendous amount of resistance. Depending on the specific LDR in use, its resistance can be anywhere from over 100KΩ to well over 2MΩ. When exposed to bright light, a LDR's resistance drops drastically. Again, based on the LDR, it may be to 5KΩ or below or to about...

Read More

what are Infrared LEDs ?

Infrared LEDs are just like ordinary LEDs but the light output cannot be seen. To view an infrared LEDs, turn it on with the appropriate battery and dropper resistor and view it with a camera. You will see the illumination on the screen. Infrared LEDs are sometimes clear and sometimes black. They operate just like a red LED with the same characteristic voltage-drop of about 1.7v. Sometimes an infrared LED is pulsed with a high current for a very...

Read More

Laser Ray Effect using 555

This circuit produces a weird "Laser Ray" sound and flashes a  LED at approx 5Hz.  COMPONENTS USED: 1.one 555 IC 2.one 100nF Ceramic Capacitor 3.one 10uF Electrolytic Capacitor 4.one 220K resistance 5.one 470ohm resistance 6.one LED 7.one 8ohm Speaker 8.one 6-12v supply ...

Read More

Delayed Start Circuit using 555 IC

This circuit does not turn on for XX seconds after power is applied. Adjustable from 1 second to 2 minutes.The delay can be adjusted by changing the resistance between pin 6 and ground. Either you can use a 1M Variable Resistor or use different resistances to get different delays in turning on the circuit. Just Connect a LED to pin 3 of 555 along with a resistor to delay the start of LED. Resistances Between pin 6 and Ground and their Respective...

Read More

Toggle LED on off using 555

This circuit will toggle the output each time the switch is pressed. The action cannot be repeated until the 10u charges or discharges via the 100k. In this Project we will connect an LED to the pin 3 of 555,when the button will be pressed the LED will toggle on off. COMPONENTS REQUIRED : 1.one 100k Resistor 2.two 10k Resistor 3.one 555 IC 4.one 10uF Electrolytic capacitor 5.one push button 6.one 470ohm/220ohm resistor 7.one LED 8.one...

Read More

LED Fading/Blinking using 555 IC

This circuit makes a LED fade on and off.  first charges a 100u and the transistor amplifies the current entering the 100u and delivers 100 times this value to the LED via the collector-emitter pins. The circuit needs 9v for operation since pin 2 of the 555 detects 2/3Vcc before changing the state of the output so we only have a maximum of 5.5v via a 470R/220R resistor to illuminate the LED.   COMPONENTS REQUIRED: 1. one 470ohm...

Read More

Transistor Tester using 555 IC

The 555 operates at 2Hz. Output pin 3 drives the circuit with a positive then zero voltage. The other end of the circuit is connected to a voltage divider with the mid-point at approx 4.5v. This allows the red and green LEDs to alternately flash when no transistor is connected to the tester. If a good transistor is connected, it will produce a short across the LED pair when the voltage is in one direction and only one LED will flash. If the transistor...

Read More

Making Traffic Lights using 555 IC

Here's a clever circuit using two 555's to produce a set of traffic lights for a model layout.  The red LED has an equal on-off period and when it is off, the first 555 delivers power to the second 555. This illuminates the Green LED and then the second 555 changes state to turn off the Green LED and turn on the Orange LED for a short period of time before the first 555 changes state to turn off the second 555 and turn on the red LED. A supply...

Read More