#10 minute alarm generator

We will be discussing all the four-timer circuits (1Min, 5Min, 10 Min and 15 Min timer) one by one throughout this article. The main role in this circuit is played by the 555 Timer IC. We can use the different timer circuits of a different time delay to operate an alarm, a device, motors, etc. To create the timer circuit for the desired time interval, simply change the value of the resistor R 1 or Capacitor C 1. We can use this oscillating behavior of 555 Timer IC to create the timer circuit of different time delays. Which means that the output pin3 of 555 Timer IC is in “OFF” condition for some time and again comes in “ON” condition after a pre-set time interval. Also, 555 Timer is used to generate an oscillating pulse. Here, with the help of the 555 timer IC, we are eliminating the need of manually switching ON or OFF the device. In this project, we are using 555 Timer IC to create various timer circuit like 1 min timer circuit, 5 min timer circuit, 10 min timer circuit, and 15 min timer circuit. In other words, if you are looking for an automated device to work for a certain time period and switch off after the desired time then this Timer Circuit is the best choice to opt. Timer circuits ease your day to day tasks in many ways by initiating or doing it in a definite time interval. Much longer delays can be achieved by selecting an FET with lower Vp than 1.5 V, and higher values of C1.In the era of technologies, everyone is taking the help of machines to simplify their life. Now, when S1 is released, C1 begins slowly discharging through R1, until the potential across C1 drops to Vp of the FET.Īt this instant Q1 turns ON again, and Q2 BJT turns OFF, reverting to its original standby state. In the stand-by powered mode, the FET Q1 is in the switched ON condition, the BJT Q2 remains switch OFF, and the relay will be deactivated in its N/C position.Īs soon as the timer is initiated by pressing the 'initiate' switch, the capacitor C1 begins charging rapidly with the -12 V, which cuts off the FET and switches ON the BJT. The below shown 10 minute simple timer is a form of enhnaced Schmitt trigger, using a combination of an FET and a BJT. This in turn allowed perfect accuracy for the capacitor charge/discharge cycles and produced uniform, consistent timing intervals for each subsequent cycles. This ensured after each timing cycle when the BC557 switched OFF allowed the capacitor's residual charge to completely discharge via the 1K/1N4148 link and the relay coil. I realized the issue and solved it by adding the 1K/1N4148 feedback link across the BC557 collector and the 1000uF capacitor positive pin. This was because of the inconsistent discharging of the 1000uF capacitor which caused inaccurate timing outputs for each subsequent timing cycles. The reset button at pin15/12 of the ICs can be used for resetting the circuit to original state.

Where Cx = required value, Cr = random value capacitor (in uF), Rm = time interval noted from Cr (in seconds) Once the interval is known, the value of Cx for achieving 1 minute time may be calculated with the following formula:

The IC 4017 is wired in its ususal decade counter mode wherein its outputs shift a logic 'high' across its pin3 to pin6 in response to every single minute pulse by the IC 4060 at its pin#14.Īs requested three LEDs are positioned for indicating the elapsing of 5 minutes, 6 minutes and 7 minutes in sequence across the pin1,5,6 respectively, with the relevant selected colored LEDs.įor setting up the IC 4060 with 1 minute intervl at its pin3, we initially use a randomly selected low value capacitor for Cx and then note down the interval at pin3 for this capacitor.

#10 minute alarm generator

In the shown 1 to 10 minute timer with display circuit, IC 4060 is configured as a 1 minute clock generator which is acquired at its pin#3. I would also like to have a seven-segment display show the elapsed time. I would like for it to light a Green LED after 5 mins, then turn off the green LED and light an Amber LED at 6 mins, and then turn off the Amber LED and light a Red LED as well as sound a buzzer at 7 mins. I want it to have an On/Off switch to power the circuit and a Start/Stop button as well as a Reset button. I have a bunch of parts already and I would like to use them if possible. I am trying to build a circuit to help me with giving speeches.