This circuit is like a mini stopwatch with a built in buzzer.
It uses a special chip IC 4060 to count the seconds like a tiny clock.
You can set the timer for a certain amount of time, and when that time is up, the buzzer goes off to remind you, just like a kitchen timer or a countdown clock.
This circuit is great for all sorts of things, like reminding you to take cookies out of the oven or letting you know when it is time to take a break.
Circuit Working:
Parts List:
| Category | Component | Quantity | Notes |
|---|---|---|---|
| Resistors | 2.2M | 1 | |
| 18k | 1 | ||
| 1M | 1 | ||
| 1k | 2 | ||
| Potentiometer | 500k | 1 | |
| Capacitors | Ceramic 220nF | 1 | |
| Ceramic 10nF | 1 | ||
| Semiconductors | IC 4060 | 1 | |
| Transistor BC547 | 1 | ||
| Diode 1N4148 | 1 | ||
| LEDs | Any 5mm 20mA | 1 | |
| Other | Buzzer | 1 | |
| ON/OFF Switch | 1 | ||
| Battery 9V | 1 |
This uncomplicated alarm timer circuit employs the 4060 integrated circuit featuring an integrated oscillator known for its stable performance over a broad frequency range.
In the circuit diagram, the oscillator frequency is determined by the RC network connected to pins 9, 10 and 11.
When the timer with alarm circuit is activated by S1 the pulse generated at the common point of R4 and C2 resets the counter, initiating the counting process.
Upon reaching the 14th bit, pin 13 transitions to a high state activating the self oscillating buzzer powered by control transistor T1.
The time interval is adjustable using P1.
To achieve intervals ranging from one minute to two hours it is essential to appropriately select the oscillator components:
- 1 to 30 minutes: C1=220nF, P1=500k
- 1 to 60 minutes: C1=470nF, P1=500k
- 1 to 120 minutes: C1=470nF, P1=1M
The timer alarm is powered by a 9V battery.
The presence of LED D1 does not impact the circuits operation and is included solely to indicate its functionality making both R3 and D1 optional components.
If the timer alarm is intended for kitchen use S1 can be a tilt sensitive switch with mercury.
When the buzzer is active, the power consumption of the timer alarm is approximately 10 mA.
Formula:
Below mentioned is the formula for timer IC 4060 from the above circuit diagram:
For RC Oscillator:
The formula to calculate the oscillation time T of the 4060 with an RC network is:
T = 2.2 * R * C
where,
- T is the time in seconds
- R is the resistance connected to pin 10 in ohms
- C is the capacitance connected to pin 9 in farads
Important Notes:
The resistor connected to pin 11 should be larger than ten times the value of the resistor connected to pin 10.
Since the 4060 has a maximum division ratio of 214 (16384), this limitation should be taken into account when choosing the frequency and desired timing.
Datasheets or other resources that offer tables with pre calculated values for common component choices can be useful for specific timing calculations.
How to Build:
To build a Simple Timer Circuit with Alarm using IC 4060 below are the steps for connections:
- Connect pins 9, 10 and 11 of the 4060 IC to an RC network consisting of R1, R2, C1 and P1.
- Use the values specified in the original text based on the desired time intervals.
- Connect pin 3 of the 4060 IC to the base of the NPN transistor T1, and connect the emitter of T1 to ground.
- Connect the collector of T1 to one terminal of the buzzer.
- Connect the other terminal of the buzzer to the positive terminal of the power supply.
- Connect pin 16 of the 4060 IC to VCC positive supply voltage.
- Connect pin 8 of the 4060 IC to the negative terminal of the power supply.
- Connect pin 7 to ground through R3 resistor and D1 LED.
- Connect pin 11 to pin 3 through a diode D2 1N4148.
- Connect pin 3 of the 4060 IC to the common point of R4 and C2.
- Connect the other terminal of R4 to the negative terminal of the power supply.
- Connect S1 switch between battery positive and the circuit positive line.
- Finally, connect the positive and negative terminals of the power supply to the respective points in the circuit.
Note:
- Ensure the connections are secure and there are no short circuits.
- Adjust P1 to set the desired time interval and the circuit should function as an alarm timer.
Conclusion:
The Timer Circuit with Alarm using IC 4060 is a practical and efficient solution for creating timed events or alarms.
Its simple design and versatile nature make it suitable for a wide range of applications from kitchen timers to reminder alarms.
By utilizing the IC 4060s integrated oscillator and binary ripple counter this circuit provides a reliable timing mechanism that can be easily adjusted and configured to meet specific timing requirements.