7815 Voltage Regulator Symbol, Features, Mnufacturer and Working Principle

Ⅰ. Overview of 7815 voltage regulator

Ⅱ. 7815 symbol, footprint and 3D models

Ⅲ. Features of 7815 voltage regulator

Ⅳ. Manufacturer of 7815 voltage regulator

Ⅴ. Technical parameters of 7815 voltage regulator

Ⅵ. How does the 7815 voltage regulator work?

Ⅶ. 7815 regulated power supply circuit diagram

Ⅷ. Applications of 7815 voltage regulator

The 7815 voltage regulator is a widely used electronic component. This article mainly introduces its basic concepts, features, manufacturer, technical parameters, working principle and applications so that you can better understand this voltage regulator.

7815 is a three-terminal positive voltage regulator circuit in a TO-220F package that can provide a variety of fixed output voltages. It is widely used in various occasions and contains overcurrent, overheating and overload protection circuits. By connecting appropriate external components to the circuit, we can obtain a variety of voltages and currents. It is a low-noise, low transient response time, high-efficiency voltage regulator tube that can effectively stabilize the output voltage and smooth the output current. At the same time, it has an extremely low overload protection mechanism. Beyond that, it dissipates very little power. We can adjust the power dissipation according to actual needs and add a radiator inside the container to protect the performance of the voltage regulator tube.

Replacements and equivalents:

• KA7815

• LM7815

• UA7815

• Large output current: The 7815 chip is capable of delivering a substantial current while ensuring a consistent output, making it well-suited for electronic devices with higher current demands.

• Low power consumption: Its low power consumption helps extend battery life and improve the life of the device.

• Broad operating temperature range: Its operating temperature range is -50°C to 145 °C, which can adapt to working conditions in various environments.

• Broad input voltage range: It accommodates a broad input voltage range, typically spanning from 18V to 35V, allowing it to adjust to varying power input scenarios.

• Stable output voltage: The output voltage of the 7815 chip is very stable and can meet the power supply needs of various electronic devices.

• Multiple package forms: It facilitates the utilization of various package forms such as TO-126 and TO-220, providing users with convenience for diverse applications.

The 7815 voltage regulator is manufactured by Keystone Electronics. Keystone Electronics Corp. is a leading global manufacturer of precision electronic interconnect components and hardware and precision stamped products, providing products manufactured from metallic or non-metallic materials for all industries. Founded in 1981, the company is committed to the design and manufacture of Keystone brand products, as well as high-quality offshore OEM/ODM manufacturing services such as security systems, portable test instruments, RF products, MP3 and computer accessories.

Step One: Bridge Rectifier

Usually, before using 7815, we need to rectify the AC voltage to convert it into DC voltage. The 75AB series integrated circuits usually use full-wave bridge rectification. Full-wave bridge rectification rectifies the AC voltage through four identical diodes and a gate-coupling transformer (some integrated modules have integrated transformers) to obtain DC power.

Step Two: Filter Capacitor

Since the current still fluctuates to a certain extent after rectification, in order to stabilize the output current, we usually add a large filter capacitor to the input end of the 7815. This capacitor mainly smoothes the voltage through filtering, providing a more stable input environment for subsequent voltage stabilization.

Step Three: Voltage Stabilization 

When the input voltage stabilizes, the 7815 starts working. It controls the stability of the output voltage according to changes in input voltage. When the input voltage rises, the 7815 reduces the output voltage, thereby counteracting the rise in input voltage. When the input voltage drops, the 7815 increases the output voltage, thus counteracting the drop in input voltage. This regulation control uses an internal feedback circuit and is proportional to the output voltage.

Step Four: Collector

Since the 7815 chip consumes power and generates heat internally, in order to ensure its normal operation, we need to use appropriate heat dissipation methods. A common approach is to install a heat sink or radiator and make sure it has good contact with the air. It should be noted that this does not mean that the chip is suitable for all high current applications.

Step Five: Overload And Short Circuit Protection

To safeguard the 7815 from potential harm due to excessive loads or abrupt changes in current, a protective device is essential. This device acts swiftly in the event of load overcurrent, short circuits, and similar occurrences, cutting off power promptly to avert damage resulting from overload.

This circuit is symmetrically connected by a pair of 7815 and 7915 three-terminal voltage regulators to obtain a set of positive and negative symmetrical regulated power supplies. The output voltage value can be adjusted independently or synchronously.

The circuit is as shown in the figure. The AC dual 18V voltage output by the transformer is rectified by D1 to D4, and filtered by C1 and C2 to obtain a DC voltage. The center tap of the dual power supply of the transformer serves as the common ground terminal. Next, we connect the positive and negative poles of the DC voltage to pin 1 of 7815 and pin 3 of 7915 respectively. The pin 3 of 7815 is connected to the sliding contact "d" of the potentiometer W2. The pin 1 of 7915 is connected to the sliding contact "C" of the potentiometer W1.

When sliding the contact piece "C" to the "O" end, we adjust W2 to get a positive variable voltage of 6 to 15V from the "a" end. On the contrary, if the contact piece "d" is slid to the "O" end, we can adjust W1 to get a negative variable voltage of 6 to 15V at the "b" end. If W1 and W2 are replaced with coaxial potentiometers, the adjustable power supply will show positive and negative symmetry, and the output voltage value can be continuously adjusted between 6V and 15V. Such a design can realize synchronous adjustment function.

• Power adapter: It is often used in power adapters to ensure stable output voltage for various devices and applications.

• LED lighting: In some LED lighting applications, the 7815 chip can be used to provide stable power supply to ensure that LED lamps operate at stable brightness.

• Linear regulator: It offers a consistent low-voltage output, combining the benefits of minimal power consumption and reduced noise, ensuring a reliable and uninterrupted energy supply for equipment.

• Communication equipment: The 7815 voltage regulator is applicable in communication devices to lower the input voltage to an appropriate range, ensuring a steady power supply for different components within the equipment.

• Automotive systems: Automotive electronics require stable voltage levels to protect sensitive components from voltage spikes that can cause potential damage. 7815 regulators are commonly used in a variety of automotive systems, including lighting controls, dashboard instrumentation, and engine control units (ECUs).

Frequently Asked Questions

1. What is the PIN configuration of IC 7815?

The 7815 ic have 3 pins, Pin 1 is a positive input, Pin 3 is a positive output and pin 2 is negative common ground between both input as well as output voltage.

2. What is 7815 voltage regulator?

7815 provides +15V regulated power supply. Voltage Step Down Converter IC. 7815 is a voltage regulator integrated circuit. Its voltage source in a circuit may have fluctuations and would not give the fixed voltage output. The voltage regulator IC maintains the output voltage at a constant value.

3. What is the function of IC 7815?

They provide a constant output voltage for a varied input voltage. The name 7815 signifies two meanings, “78” means that it is a positive voltage regulator and “15” means that it provides 15V as output. So our 7805 will provide a +15V output voltage.

4. How do you use 7815?

You can use a 7815 positive regulator like any other electrical equipment in a circuit. Importantly, use it with two capacitors to make the regulator produce reliable results. For example, one of 0.1Uf and the other should be the 0.33Uf value. Usually, the 0.33Uf capacitor is the input capacitor.

5. How does a voltage regulator work?

To maintain a constant output voltage, the linear regulator adjusts the pass device resistance by comparing the internal voltage reference to the sampled output voltage, and then driving the error to zero.