NE555 precision timer IC is one of the most important precision timer IC. There is a huge list of projects that can be built by using 555 Timer ICs. NE555 Timer IC is also considered to be an ideal IC since it offers multiple features like multipurpose functionality, low power consumption, small size, and durability. In this project, we are going to design a simple 555 Precision Timer tester circuit.
This 555 Precision Timer tester, allows us to make sure that this integrated circuit works properly.
Hardware Components
You will need the following parts to build this circuit.
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | precision IC | NE555 timer | 1 |
| 2. | Resistor | 69KΩ, 40KΩ, 390Ω | 1,1,1 |
| 3. | Capacitor | 1μF, 10nF | 1,1 |
| 4. | Battery | 9V | 1 |
| 5. | Connecting Wires | – | 1 |
| 6. | LED | 5mm | 2 |
| 7. | Breadboard | – | 1 |
555 Timer Pinout
| Pin No. | Pin Name | Description |
| 1 | GND | Ground |
| 2 | TRIG | Trigger, set to 1/3 of Vcc |
| 3 | OUT | Timer Output |
| 4 | RESET | Reset active low |
| 5 | CONT | Comparator threshold control |
| 6 | THRES | Threshold, set to 2/3 of Vcc |
| 7 | DISCH | The low impedance discharge path |
| 8 | Vcc | Chip supply voltages (6v-12v) |
Circuit Diagram
Working Explanation
In this circuit, the NE555 is wired as an astable multivibrator. On completing the circuit, the LEDs D1&D2 will flash alternatively. That is when the output is high D1 will glow & when the output is low D2 will glow. The frequency of flashing will depend on components R1 (69KΩ), R2 (40KΩ) & C1 (1μF).
When there is a continuous supply, C1 will start charging through R1&R2. When the voltage across C1 gets above 2/3rd of the supply voltage the internal Flip Flop toggles. Pin 7 becomes low & C1 starts discharging. When the voltage across C1 goes below 1/3rd of the supply voltage the internal flip flop resets & pin7 becomes high. The C1 again starts charging. All these operations will take place if the IC is healthy. According to the frequency of this charging & discharging, the LEDs will flash. Through this procedure, we can conclude if the IC is healthy or not.
Applications
- Generally used to determine the health & working capacity of 555 timers ICs.
