Use case of A1015 and C1815


The A1015 is a PNP general-purpose transistor with low voltage and low power capabilities, making it more reliable for use in a wider range of applications. Normally, a transistor is used as a switch or an amplifier. It can switch on or off the loads with voltages upto 50V. It can be utilized in Darlington pairs, audio amplification, and driver stage amplification. The current gain of the A1015 transistor will range from 70 to 400. A1015 is mostly used in audio frequency amplifier applications. The A1015 transistor's maximum collector current is -150ma. The power dissipation is 400mw. The transition frequency is 80 MHz. The main use of A1015 is for audio frequency amplifier and switching  applications.


A1015 transistor





A1015 water level indication circuit


Three PNP transistor switches are used in this water level indication circuit. Each transistor turns on to drive the corresponding LED when its base is supplied with current through the water by the electrode probes. 

When the water level rises, the base of each transistor connects to 9V DC via the water and the corresponding probe. This, in turn, makes the transistors conduct and glow LED to indicate the level of water. Setup the probes in order on a PVC pipe according to the depth and immerse it in the tank. When the water level is low then Red LED will glow, When water level is medium Yellow LED will glow, When water tank is full then Green LED will glow.




C1815 is an NPN bipolar junction transistor.  It's a high-frequency oscillator and audio amplification device (OSC). This transistor's collector-base voltage is 50V. T the transistor's collector current is 150 mA, it can drive any load that is less than 150 mA. The power dissipation is 400mw. The value of voltage across the collector to the emitter(VCE) is 50V.  The voltage across its emitter and base (VEB) is 5 volts. Voltage across collector and base (VCB) is 60V.


C1815 transistor


C1815 as an amplifier 


C1815 transistor as an amplifier

When in the Active Region, a transistor operates as an amplifier. It has the ability to amplify power, voltage, and current. The most popular and commonly used configuration is the common emitter type. The input is always applied at the forward-biased junction in the amplification transistor circuit. Similarly, the output can be collected across the reverse-biased junction of the transistor. The input signal is applied to the base-emitter junction, and the output signal is sent through the load to the emitter-collector junction.



A1015 transistor pin out
C1815 transistor pin out




Transistor A1015 C1815
Package T0-92 TO-92
Collector base Voltage -50V 60V
Collector emitter Voltage -50V 50V
Emitter base Voltage -5V 5V
DC Current gain 400 700
Collector current -0.15A 150mA
Transition frequency 80MHz 80MHz
Collector Dissipation 200mW 400mW
Max. Junction temperature 150 Degree C 150 Degree C


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