An 8050 transistor is a small device used to channel electrical currents in portable radios. The number “8050” is basically an indication of size and specific output ratings. Engineers and electronics experts usually give transistors numerical names to make it easier to identify and differentiate them. Those with the 8050 specification are usually made of silicon, and operate as part of a push-pull application system. The mechanics of how these and other transistors work on an electrochemical level can be somewhat complex, but in general, they direct and channel charges with a series of polarized ions. They usually work in conjunction with amplifier circuits; in the case of the 8050, the complement is typically the 8550. The technical ratings of 8050 and 8550 transistors are usually identical. The difference is in their polarity. Together, they allow safe flow of current through and in radios, which powers transmissions and allows for a number of functions on the user’s end.
Electrical currents are often a lot more powerful than people realize. Simply plugging a device into an outlet will access flows, but in most cases these flows have been tempered both at the outlet and basic wiring level, and also within the device, which is to say, whatever is being plugged in. Devices usually have complex internal structures to channel and direct currents within the inner workings to both temper them and bring them where they need to go. Transistors are one of these things. The 8050 type transistor is a very specific device that is classed as a negative-positive-negative (NPN) epitaxial amplifier transistor and is most commonly seen in radios.
The 8050 transistor and its 8550 equivalent were designed to be used as a complementary pair of transistors in low-power push-pull amplifier applications. In general, the 8050 transistor is a 2-watt amplifier with a maximum collector-emitter current of 1.5 amps and a maximum collector-emitter voltage of 25 volts.
Understanding Transistors Generally
A basic transistor is a semiconductor device that is created by placing a layer of semiconductor material between two layers of material with opposite polarity. An NPN transistor such as the 8050 usually has a layer of positive material lying between two layers of negative material. A positive-negative-positive (PNP) transistor, by contrast, has a negative layer between two positive layers.
Each of the layers in a transistor has a lead attached to it. The resulting terminals are known as the emitter, the base, and the collector. The base is always the middle layer.
How it Works
A transistor is basically an electronic switch. A supply voltage and a load are wired through the collector and emitter terminals. With no voltage applied to the base terminal, the transistor is off. When a voltage of the correct amplitude and polarity is applied to the base terminal, the transistor switches on, allowing a much larger current to flow between the emitter and collector terminals.
The voltage that is required to control the on-off state of the transistor is usually pretty small. The transistor, therefore, can be used as an amplifier. The base-emitter circuit controls the current flowing through the emitter-collector circuit.
A silicon transistor like the 8050 typically switches on when the base voltage is 0.65 volts higher than the emitter. The emitter-base circuit is normally set up to provide a preset voltage that is close to the trigger point. This is known as the bias. While the transistor is conducting, the output follows the pattern of the input.
In most cases, 8050 transistors can be set up to amplify the entire input waveform if the voltage of the entire waveform is above the trigger point of the transistor. This means that the transistor will be conducting even when no input is applied, and it creates a very noisy output. One of the main reasons engineers designed push-pull amplifiers was to prevent excess noise and to create a more efficient circuit.
A push-pull amplifier uses two transistors of opposite polarity. When the input wave form is in the positive half of the cycle, the NPN transistor will conduct, and the PNP transistor will switch off. If the input signal swings negative, the PNP transistor will conduct and the NPN transistor will switch off. The two outputs are combined to produce the complete amplified signal.