How to make a 12V power supply?

Hello, you can make a 12V power supply with the picture you gave, the easiest way is to use LM7812.

I was lazy to find it from the data sheet. In fact, the CI and CO can be combined with an electrolytic capacitor of 100 to 470 UF, respectively. For 12V output, the input voltage must not be less than 14V.

The design is calculated like this, the voltage between pins 2 and 3 is, and the resistance you choose is 200 ohms, so: 200=(:r2. Calculate r=, you can choose a 2k potentiometer.

It is recommended that you change the 200 of R1 to 2K, so that R2 can choose a 20K potentiometer. Not for anything else, your current is too big, the current on R1 and R2 is more than 6mA, there is no need to make it so big, the potentiometer is easy to damage under high current.

To make a 12V regulated power supply, the simplest circuit is to use the 7812 three-terminal regulator IC to make it, but this three-terminal regulator IC is a linear regulator IC, and when the input voltage is high or the output current is large, it heats up.

Severe. Over here.

Introduce a 12V regulated power supply made by LM2596, a DC-DC buck regulator IC, which has a simple circuit and stable operation, with a maximum input voltage of 40V and an output current of up to 3A.

The LM2596 is a 12V 3A regulated power supply.

Introduce a 12V regulated power supply made by LM2596, a DC-DC buck regulator IC, which has a simple circuit and stable operation, with a maximum input voltage of 40V and an output current of up to 3A.

The LM2596 is a 12V 3A regulated power supply.

The LM2596 is a commonly used DC-DC step-down regulator IC with an input voltage of up to 40V (the high-voltage version of the LM2596HV can reach a maximum input voltage of 60V) and an output current of up to 3A.

This circuit is very simple, as long as the components are good and the soldering is correct, it can work without debugging. When working under high current, the LM2596 should add a heat sink with a suitable area.

LM2596-12 in TO-220 package.

LM2596-12 in TO-220 package.

There are many output voltages of the LM2596, among which the output voltage of the LM2596ADJ is the same as that of the LM317, which is adjustable. For the convenience of production, LM2596T-12 is selected here, and its output voltage is a fixed 12V voltage.

Toroidal inductance with high current.

Toroidal inductance with high current.

When making, the diode VD in the figure should be a 3A Schottky diode such as 1N5822 and SR360.

The inductor l is a toroidal inductor with a current of 3A. Thank you.

It's easy to make 12V and 5V power supplies – it's that simple.

For the DC voltage of 12V, two diodes can be connected in series at the positive output end (the current should be adapted to the needs), so that the voltage drops to 10V, followed by two equivalent resistors in series, indirectly, the output is plus or minus 5V. The current in the resistor is larger than the current required by the load behind it, so that the output voltage is relatively stable.

The capacitor here is generally selected CBB capacitor, the larger the capacitor capacity, the smaller the capacitive reactance of the capacitor, and the greater the current that can be output, this scheme is not suitable for high-power load equipment, and the input and output are not isolated, so it needs to be used with caution.

If you want a positive 5V voltage, use 7805, 12V is connected to the input of 7805, 12V is connected to the common terminal (the middle pin of 7805), the output output is 5+, and the negative terminal of the output terminal is 12V negative.

If you want negative 5V, use 7905, 12V negative connection to the input end of 7805, 12V + to connect to the common terminal (the pin in the middle of 7905), output 5-, output positive terminal 12V positive pole.

It is also possible to use 7805 voltage regulation or LM337.

Summary. How to make a 2v10 mA power supply.

1. Negative power supply: Select a DC power supply and define the positive pole of the power supply as zero potential, that is, the positive pole of the power supply is connected to the system, and the power supply is usually called the negative power supply.

2. Positive and negative power supply: select two DC power supplies E1 and E2, the negative pole of E1 is connected to the positive pole of E2 and is defined as zero potential (connected to the system ground), and the group of power supplies is usually called positive and negative power supply.

3. Three-terminal integrated voltage regulator: positive power supply 78xx series, negative power supply 79xx series.

How to make a 2v10 mA power supply.

How to make a 2v10 mA power supply 1, negative power supply: select a DC power supply, the positive pole of the power supply is defined as zero potential, that is, the positive pole of the power supply is connected to the system, and the power supply is usually called a negative power supply. 2. Positive and negative power supply:

Two DC power supplies E1 and E2 are selected, and the negative pole of E1 is connected to the positive pole of E2 and is defined as zero potential (connected to the ground of the system), and the chain group power supply is usually referred to as the positive and negative power supply. 3. Three-terminal integrated voltage regulator: positive power supply 78xx series, negative power supply 79xx series.

Is it OK to use a size 5 battery?

I only need to use 10 milliamps.

1. The simplest is a power resistor, a 5V regulator diode, the load is connected in parallel on the 5V regulator, which belongs to the parallel internal regulator, the efficiency is low, the capacitance resistance and the regulator tube consume a lot, the output power is very related to the power current of the regulator tube, and it is usually used in tens of mA small current places.

Look at Figure 1, the resistor is selected as 68 ohms 2W, and the regulator tube is selected as 2W power, and the maximum output current is 100mA.

2. Serial resistance and 10-12 silicon diodes (diodes can be replaced by a 7V power regulator tube, and the current output is not as large as the diode), which belongs to a simple series voltage regulator circuit, the advantage is that if the load current is large, the current value depends on the positive conduction current of the diode, and the current can reach the amperage level (the power supply needs to output 12V sufficient current), if it is a fixed current, you can choose the resistance value of the power resistor to reduce the number of diodes in series.

Look at ** two. 3,5V three-terminal regulator, it can be said that it is a very simple circuit, the regulator model is different, the output current value is amperes, three pins, in, ground, out, respectively connected to the power line. The disadvantage is that the efficiency is low, the output current is large, and the power consumption on the regulator block = (12-5V x The current is large, and a heat sink needs to be installed.

Look at ** three. 4. Switching regulator, you can buy a switching power supply with an output of 1A for ten yuan, which is small in size, efficient and low in heat.

Of course, there are very simple circuits, all you need is a regulator diode and a current limiting resistor (or a regulator diode plus a triode). However, such a circuit is less efficient, especially when the output current of a 5V power supply is required, and it is not easy to use an overly simple circuit.

Whether it can be as simple as the specific circuit depends on the specific circuit.

The simplest is a power resistor, a 5V regulator diode, the load is connected in parallel on the 5V regulator tube, which belongs to the parallel regulator, the efficiency is low, the resistance and the regulator tube consume a lot, the output power and the power current of the regulator tube are very related, usually used in tens of mA small current places.

Looking at the figure, the resistance is selected as 68 ohms 2W, and the regulator tube is selected as 2W power, and the maximum output current is 100mA.

Extended information: Power supply is a technology product with power electronics as the core. "Power supply" is the end product, and "power supply" product is the specific product embodiment of "power electronics" application technology. Power electronic power supply usually refers to power products that use power electronics technology, and is an important component of power electronic equipment.

The power supply industry with power electronics as the core technology is the foundation for the development of various high-tech industries, and all high-tech equipment needs the technical support of power electronic power supply.

With the rapid development of the T industry, the C industry, and the P C machine. Drive the take-off of the power supply industry. The power supply industry is widely used in all walks of life and is inseparable from the national economy.

At the same time, with the gradual deepening of China's reform and opening up, the number of foreign-funded enterprises and joint ventures has gradually increased, which has intensified competition, and is also an opportunity and challenge for local enterprises.

For the operating conditions of power supply enterprises, due to the overall strong demand, although the competition has intensified, the average income and profit of the industry have increased. At the same time, in order to have the potential for further competition in the future, China's power supply companies have increased their R&D efforts and increased R&D personnel. From the 90s of the last century, the power supply industry has developed in the first way, the number of enterprises has increased from hundreds in the early 90s to tens of thousands, and the output has increased from more than one billion yuan in the 90s to tens of billions of yuan so far.

And it is still developing at a rapid pace.

A switching regulator chip CS5171 is recommended, which can realize a variety of functions such as boost, step-down, inverting, positive and negative symmetrical dual power output. Input voltage range, maximum output current. The figure below is a practical circuit with a CS5171 symmetrical dual power supply of plus or minus 12V

The voltage is not enough, 26V is enough. Boost first, give you a boost chip.

The output voltage can be adjusted by changing the value of R2.

Buck-boost chip MC34063

Input Voltage Range:

Output voltage adjustable range:

The output current can be up to:

Working frequency: up to 100kHz

MC34063 Boost Circuit.

The principle of the step-down circuit composed of MC34063 is shown in Figure 8, when the switch tube (T1) in the chip is turned on, the power supply is grounded through the sampling resistance RSC, the inductor L1, and the 1 and 2 pins of the MC34063, at this time, the inductor L1 begins to store energy, and C0 provides energy to the load. When T1 is disconnected, both the power supply and the inductor supply energy to both the load and the capacitor CO. During the release of energy from the inductor, the voltage obtained on the load is higher than the supply voltage because the polarity of the electromotive force at both ends of the inductor is the same as the polarity of the power supply, which is equivalent to two power supplies in series.

The frequency at which the switch tube is turned on and off is called the operating frequency of the chip. As long as the time constant of this frequency is high enough relative to the load, a continuous DC voltage can be obtained on the load.

1. TDA2030 is a power amplifier, and the circuit diagram indicates that it needs to be powered by dual power supplies, not dual power supplies.

2. It is advisable to use two batteries for power. Because the principle is simple.

Here is connected to "Assume the ground, the battery above" + "Extremely positive power, the battery below" - "Extremely negative power.

The 20V power supply and a power resistor charge battery 1 and battery 2 respectively. Power the amplifier board when the battery is fully charged.