Typical common-base current gain in a well-designed bipolar transistor is very close to unity.If it is a matter of voltage, and not dBm power, just use a broadband transformer wound on a ferrite core. The current gain for the common-base configuration is defined as the change in collector current divided by the change in emitter current when the base-to-collector voltage is constant. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. NPN, or “sinking” output sensors, work in the opposite way, sinking ground voltage to an input when it's on.Ī transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. PNP sensors produce a positive output to your industrial controls input, while NPN sensors produce a negative signal during an “on” state. 2N3904 has a gain value of 300 this value determines the amplification capacity of the transistor. It is designed for low current and power, medium voltage, and can operate at moderately high speeds.ĢN3904 is a NPN transistor hence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground and will be closed (Forward biased) when a signal is provided to base pin.

The 2N3904 is a common NPN bipolar junction transistor used for general-purpose low-power amplifying or switching applications. Circuit 8: The non-inverting circuit uses a pair of complementary NPN type ( 2N3904) and PNP type (2N3906) transistors.Circuit 7: How to design a 13.56mhz sine wave power amplifier circuit with 2N3904.Circuit 6: 2N3904 Sample Circuit-Amplifier.CatalogĬircuit 1: Thermostat controller composed of LM75 intelligent temperature sensor and 2N3904 transisitor Hope these circuit diagrams are helpful to you. These circuit diagrams are basically beginner-friendly types. In this blog, Apogeeweb has prepared 8 simple 2N3904 circuits for electronics enthusiasts.

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