7805 010100

7805 is a three terminal positive voltage regulator, designed primarily to provide a 5 V power supply. In addition to its use as a 5 V regulator, it can also be used as a pre-regulator for other regulator ICs. 7805 is an 8-pin integrated circuit (IC). It is a linear voltage regulator, meaning it maintains the output voltage at a fixed value as long as the input voltage remains in a given range. This range is typically up to 35 V, with a 5 V output.

7805 has some features that make it a very useful IC, such as low price, low heat dissipation, and easy availability. It can also be used as a substitute for other types of voltage regulators, such as Zener diodes, when the range of required voltages is relatively low. 7805 is available in standard packages, as well as several other shapes and sizes.

The most common application of the 7805 is for providing a regulated 5 V power source for digital circuits. This can be done by connecting a 9 V or 12 V power supply to the input pin of the 7805, and connecting a 1 k ohm resistor and 0.1 µF ceramic capacitor from the output pin to ground. This reduces the noise from the power supply and ensures a steady output voltage. This arrangement is suitable for most digital circuits.

7805 has also seen applications in analogue circuits. It can be used to set a voltage reference in a circuit, or to bias a transistor into its active region. Additionally, it can be used in a switching regulator to regulate a voltage, known as switching mode power supply.

The working principle of the 7805 is based on a feedback circuit that keeps the output voltage constant by adjusting the input current. The output voltage is compared to an internal reference voltage, and the error signal is used to control the base current of a power transistor. This base current turns on the transistor and releases the required amount of current to the output pin, thus maintaining the output voltage at a constant level.

7805 is widely used and is available in many versions and packages. Its low cost, high reliability, and low heat dissipation make it an ideal choice for many applications. It is often used in power supplies, motor control systems, home appliances, computers, and consumer electronic products.