Intro: 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
5K variable resistors ×2
Insulated Copper wire
Led with resistor about 100 ohms or without it as well
Step 2: 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
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.