A small blog to understand the usage of transistor through its simple applications. Created by Ajin.P.A. and Abhi Harshan for Science Fest in St. Joseph's H.S.S. Pavaratty.
Introduction
Some transistors :
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Steady Hand Game 2
Handle ring is connected to +ve of battery. When ring is moving through the wire and it touched on the wire then the red led glow and C1 charges. C maintain this glow for some time. This also keep the T1 turn off. If handle ring reached the end not touching wire the T1 turn on and green LED turn on with C.
Reminder
Amplifier
When we connect a transistor with the output of ic um 66 the sound increases 2 times. Here transistor is used as an amplifier.
Steady Hand Game
Burglar Alarm
From transmitter the laser light is produced. Place the transmitter and receiver so that the laser beam fall on LDR. When laser falls on LDR this turns off t1. When the beam split by a tress passer or burglar LDR stops conducting and t1 turns on and LED glows. C store Voltage and Maintains this glow.
Water Level Indicater
Connect the metal pins on the water tank as one at the bottom, one at the minimum level , one at maximum level and last one at the point at which the water will overflow.
Pin A is connected to +ve of battery.3 LED are showing the amount of water in the tank
The red LED(low) will be always on.
The fact is that the water is a conductor. If the level of water is between C and B, +ve charge from A will pass through B. In this way the base of t2 gets +ve charge and t2 turn on.this will turn on green led.
When the water reaches B t2 turns on and Orange LED glows.
If Water level is lower than B the t3 turn on and the siren for low water level makes sound.
If water reaches D then the t4 switches the siren for high water level.
This will be very useful to every houses.
Piano
Here transistor is used for oscillation.
Emergency
When electricity is not available PNP transistor switches and LED glows from the battery power.
This circuit acts as an emergency light. Here the switching capability of transistor is used.
Automatic Night Light
So t1 turn off. And LED doesn’t glow .
At night LDR doesn’t transfer (+)ve Charge. So there will be more (+)ve charge than (–)ve charge at transistor's base. So the transistor, turns on and LED glows
Through these operations the LED glow at night and doesn't glow at day.