Introduction: Timer or Alarm

Picture of Timer or Alarm

I was given a NE555N and I had no idea of it as I am in class 10 so after going through few books in library I found that we can make a alarm or timer from it. Hope you enjoy.

Step 1: Material

NE555N
5K variable resistors ×2
Insulated Copper wire
Soldier
Led with resistor about 100 ohms or without it as well
Capacitor any
Battery
Buzzer

Step 2: Soldiering the Components

Picture of Soldiering the Components

soilder the components as shown in image.
place a pressure button between battery and alarm if you want to make a pressure alarm .
if you want to make a timer then rotate the two variable resistors to get perfect timing like if you want to go for I sec then rotate it so that after one second the led stops for few mini second or if you want exact time for stopping the led also then also rotate the resistor from pin 6 to 7.
it is very simple and and easy to make for school projects.
if you want to make a 555 timer laser trip wire alarm then wait for few days I am working on it.
I hope you enjoy and for any query please feel free to comment.

Step 3: Pressure Switch

Picture of Pressure Switch

I made it myself using a spring and a nut bolt. cover the bolt with tape and then place the spring take the nut of bigger size and then make sure that after you place it in casing, if there is any weight over it then the nut bolt are not in contact and the moment weight is removed they meet and complete the circuit.
it is easy to make but I highly recommend you to used one available in market as it is nor sure that it will work or not and if you are using it for jewellery security then it is a bit risky to use home made.
that's all in the update.
thanks

Comments

andrey_n (author)2015-11-26

If you turn potentiometer between pin7 and + in minimum , you'll have a short circuit, and NE555 will damaged. You must add constant resistor about 1kOhm between + and this potentiometer.

RiteshYadav (author)andrey_n2015-11-28

well I am having no problem till now . may be because the resistance may be high about 4k. thanks for your advice, I will change it by a fixed resistance of 4 k.

About This Instructable

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Bio: i am in class 11 and i like making rc cars and other rc stuffs i also like making unique models .
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