Its applications may include amplification of analog signals as well as switching applications. Normally it is capable of switching a load current of 800mA which is really high rating as compared to other similar transistors. It is either made up of silicon or germanium material and doped with either positively or negatively charged material. One of its key features is its ability to handle the high values of currents as compared to the other similar small transistors. Due to the low cost and small size it is the most commonly used transistor. The major functional area of 2N2222 is enclosed in TO-18 package. I hope you have enjoyed the previous post on Introduction to ULN2003. switching and amplification of analog signals. 2N2222 can be used for different purposes e.g. Today, I am going to give you an Introduction to 2N2222. It is the most commonly used Negative-Positive-Negative (NPN) Bipolar Junction Transistor (BJT) available in the market now a days.

Usually found in devices such as screamers, PA Systems & loudspeakers.Hello everyone! I hope you will be absolutely fine and having fun.

Usage in Emergency services such as police & ambulance sirens.Civil defense uses such as alarms for early warning systems.Industrial uses such as fire & substance danger alarms.Commonly used in home security setups & monitoring systems.The tone signal from the speaker will be an increasing or decreasing tone depending on whether the circuit is switched on or off. On disconnecting the circuit from the power, the capacitor C1 discharges slowly resulting in a decreasing frequency cycle. This increasing voltage results in a decreasing time constant at the R2/C2 junction, Which also results in an increased frequency of the multivibrator. When the circuit is switched on, the capacitor C1 charges slowly till it reaches its maximum voltage level. Combined, the two transistors represent a self-triggering multivibrator. This is due to the generator part of the circuit, which is a combination of PNP (2N2907) and NPN (2N2222) transistors. This circuit produces a sound very similar to a siren.

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