Here is a 555 timer circuit project. You can use it for the snooze alarm with a buzzer. When on-time 5, 10, 15, and 20 minutes. It is easy to make and portable with small PCBs. Also… If you want to control other loads. It is easy with a relay directly. Because the output of 555 has a maximum current to 200mA.
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How it works
When we turn on switch-S1 to enter a power supply to the circuit. It will be ready to go.
The parts have a different function.
The circuit includes IC1-555 Mono Stable (timer) for the delay.
Switches S3 S6—choose a time as we want
- If turns on S3 for 5 minutes. Then, turn off the S3.
- To turns on S4 for 10 minutes. Then, turn off the S4.
- Next, it turns on S5 for 15 minutes. Then, turn off the S5.
- Last, turns on S6 is scheduled for 20 minutes.
This project uses the principle of monostable multivibrator 555. It works with a delay charge and discharges completely.
When in time that setting. It will send a signal to Pin 3 is low. But can power buzzer-BZ1 beeps out.
The time value is determined by the value R2, R3, R4, R5, and C2.
If you want to set up a long time. It increases the R and C.
The time is short. If it reduced the R and C.
Other: 555 timer projects
How to build this project
First of all, get the components from the list below. This project is very easy. Because of using a few components.
Parts you will need
IC1: NE555 timer IC
C1: 0.1µF 50V, Ceramic Capacitors
C2: 470µF 16V, Electrolytic Capacitors
R1: 22K, 0.25W Resistors, tolerance: 5%
BZ1: 9V Piezo sounder (incorporating 3KHz oscillator)
S1: the ON-OFF SPST switch
S2: Normally open pushbutton Switch
S3 to S6: small SPST Slider Switch
B1: 9V batteries
Wires, Socket IC, etc.
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Then, assemble them on a PCB as the PCB layout and the component layout.
The copper PCB layout
Or, If you want to save and quick to build You may use a perforated PCB, too.
You must be careful about some devices with terminals. For example, IC-555, Electrolytic capacitors, and buzzer.
They will are connected to match terminals only.
This project worked my son test it on the breadboard. Below!
He tests at 5 minutes.
About S3 to S6, the designer wants to use a small switch only. You can use the rotary switch. It is easy, too.
Adding Relay to control more
If you want to control more load. It is an easy way with helping of Relay. Look at the image below.
This is a simple universal timer project. You can use a relay to connect with the buzzer. To control other loads that you want.
All full-size images of this post are in this Ebook: Elec Circuit vol. 2 below. Please support me. 🙂
Check out these related circuits, too:
- The simple long duration timer circuit
- CD4060 Timer Circuit 22 seconds to 4 hours
- Simple 555 countdown timer circuit with alarm
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