How to Set a 1-Minute Timer using the 555 Timer IC

The 555 timer IC is a versatile integrated circuit that can be used to create various types of timer circuits. In this article, we will explore how to set a 1-minute timer using the 555 timer IC.

Initially, the LED will be turned ON (OUTPUT PIN 3 LOW) as soon as we press the push button and trigger the 555 via TRIGGER PIN 2. The timer will start, and the LED will become OFF (OUTPUT PIN 3 HIGH). After the calculated time duration, PIN 3 will again become LOW, and the LED will get turned ON. This means that after the calculated time, the LED will be turned ON.

It's essential to note that we have used an LED at reverse logic. When OUTPUT pin 3 is low, the LED will be ON, and when output is HIGH, the LED will be OFF.

To create a 10-minute timer circuit, we would change the resistor value to 545.4 k ohm. For a 15-minute timer circuit, we need the value of the resistor to be 818.2k ohm. Similarly, for a 5-minute timer circuit, we would simply change the resistor value to 272.7k ohm in the above-given 1-minute timer circuit.

Calculating Resistor Values

We can easily calculate the resistor value for 5-minute, 10-minute, and 15-minute timer circuits. To build a 1-minute timer circuit, we need a resistor of 55 k ohms and a capacitor of 1000 μF.

The duration for which PIN 3 remains HIGH in monostable mode is given by the formula:

R1 * C1 = T

Where R1 is the value of the resistor, C1 is the value of the capacitor, and T is the time period (in seconds).

Setting the 555 Timer to Monostable Mode

To build a timer circuit using the 555 timer IC, we need to set it in monostable mode. We can do this by adjusting the values of Resistor R1 and/or Capacitor C1.

The 555 timer IC is essentially a 'timer' that creates an oscillating pulse. It means that for some time, output pin 3 will be HIGH, and for some time, it will remain LOW, creating an oscillating output. This property of the 555 timer can be used to create various timer circuits like 1-minute, 5-minute, 10-minute, and 15-minute timer circuits.

In conclusion, setting a 1-minute timer using the 555 timer IC is relatively simple. By adjusting the values of Resistor R1 and/or Capacitor C1, we can easily calculate the resistor value for different time periods, creating various timer circuits with ease.

Set a 1 minute timer