dc converter

LM2576-5.0 is simple switching power supply 3A step down regulator for power digital circuits.

Sometimes we need to work on the car or travel outside the area. The without wires internet ADSL. When use the Internet was Using 3G aircards and distributed to the Internet via wireless. It uses the power supply of 5V 2A. Because it is digital circuit which uses a 10 watt high power ever.

When it comes to used in cars. We can uses power from the cigarette lighter of a car.But have the voltage 12 volts, so it must reduced the voltage down to 5 voltsat current is 2 amperes. We have a lot of choices. When before I use the transistor and IC-7805 for this job. However, when considered with caution. To its low performance. have high temperature and large, as the identity of the generally linear ICs. This work, we try to do the switching IC.

IC-LM2576-5.0. (DC to DC step down voltage regulator) It is a very interesting number. It maintains a constant the voltage of approximately 5 volts and current 3A. Compatible with the device easily. On the manufacturer’s manual. I smile with ease. It is very easy to use. as Figure 1. Will see that, there are only four more devices only are C1-100uF , D1-1N5822,L1-100uH, C2-1000uF. The input voltage levels is 7volts to 40volts. My favorite feature is the runs with high frequency. IC is not hot. It can hold a small cooler. And Used continuously for a long time.

Sorce:

Here is circuit switching regulator 5V 5A for digital circuit.
Use IC LM2678-5.0 is High Efficiency 5V 5A Step-Down Voltage Regulator This is good power supply, small size and do not hot.

Friends want to build the digital power supply which this circuit “Top Linear power supply regulator 5V 5A with 7812 and LM723” is good quality, but as the too old circuit. Not suitable for this era. So I to find a new and very powerful also an Energy savings.
Considering these reasons. We will Using an ICs Switching supply. Because of has very high performance. High energy, while the low energy input.
LM2678 can respond to fully our needs. We can supply approximately 5A. The circuit and very easy to use. See information on the manufacturer’s manual, very easy to understand explanations. It uses a little equipment is only 9 pieces. And Cin = 3x15uF 50V, C2-0.47uF 63V , C3-0.01uF 63V , D1 – 6TQ045S, L1-22uH, Cout=2x180uF 16V as figure 1
Advantage of this range is very wide input voltage. From 8 vots to 40 volts DC power and does not need to be very smooth. But must be have the current 5 A or more.And this circuit high performance. Generate heat loss at low IC can use a small cooler (heat sink).

Source : 97 Electron Circuit

source:

When you have a 5 volts(4-6V) power supply for digital circuits. But need to use an isolated dual power supply of +12 volts and -12 volts at current about under 300 milliampere (0.3 A). You have many options. If you want convenience, small and simple to build circuits. Also must this circuit.
Detail IC LM2587
We use the LM2587(national.com) is main that as series of regulators circuits specifically for flyback, step-up (booster) and forward converter.

Output Range 1.23V min, 5V, 12V, 3.3V
InputMin Voltage: 4 Volt
InputMax Voltage: 40 Volt

Protecting the power switch are current and thermal limiting circuits, and an undervoltage lockout circuit. This IC contains a 100 kHz fixed-frequency internal oscillator that permits the use of small magnetics.
An output voltage tolerance of ±4%, within specified input voltages and output load conditions, is guaranteed for the power supply system.

The working principle.

The LM2587-12 is ideally suited for use in the flyback regulator topology. The flyback regulator can produce dual output voltage in Figure 1 The generates an output voltage that is inside the range of the input voltage. This feature is unique to flyback
.

The primary winding of the transformer, T1, storing energy in the magnetic field of the transformer. Note that the
primary and secondary windings are out of phase, so no current flows through the secondary when current flows
through the primary.

When the switch turns off, the magnetic field collapses, reversing the voltage polarity of the
primary and secondary windings.

Now rectifier D1-D2 is forward biased and current flows through it, releasing the energy stored in the transformer. This produces voltage at the output.

The output voltage is controlled by modulating the peak switch current. This is done by feeding back a portion of
the output voltage to the error amp, which amplifies the difference between the feedback voltage and a 1.230V reference.

The error amp output voltage is compared to a ramp voltage proportional to the switch current. The comparator terminates the switch on time when the two voltages are equal, there by controlling the peak switch current to maintain a constant output voltage.

Soure:

If you are looking a ICs for a DC to DC converter job. I highly recommend of IC-LM1577/LM2577 supply all of the power and control functions for
step-up (boost), flyback, and forward converter switching regulators.

The output voltage typical : Wide input voltage 3.5Vdc to 40Vdc.
Component list
- 2.2k 1/4W resistor
- 0.1uF capacitor
- 0.33uF capacitor
- 680uF 50V electrolytic capacitor
- 1N5822 high speed schottky diode (3A)
- wire coil inductor, 100uH
- “for LM2577-adj IC” 20k multi-turn variable resistor, set to ratio to R2=2k, R1=18k for voltage output of 12Vdc before soldering
Part number:
- LM2577-12 (12Vdc output)
- LM2577-15 (15Vdc output)
- LM2577-ADJ (1.23Vdc to 37Vdc output)

Using a minimum number of external parts, these regulators are price reasonable good value., and made project easily.

Included on the chip is a 3 amp NPN switch and they have protection circuit, consisting of current and
thermal limiting, and undervoltage lockout.

Other detail within a 52 kHz stable-frequency oscillator that
no external components, a soft start mode to reduce running current during start-up, and current mode
control for rejection of input voltage and output load transients.

Source:

When you have sized batteries is 1.5V or 3V, but need a voltage 9VDC, DC converter circuit to help you for sure!

Some problems in the electronics job, can modify or bring devices come to apply available not difficult If we know the principles and limitations of those devices. As the project is being offered at this time, will be bringing sized batteries 1.5 volt connected through an electronic circuit called dc converter to increase the voltage to have higher value be 9 volt instead of the battery 6 pack, connected series.

It can also increase the voltage from the battery 3 volt to 9 volt as well be the original circuit, and it will allow more current.

Properties of the IC TL496
- A TL496 be control circuit of the power supply, by the circuit was designed, so that the output voltage is 9 volt. For the change of the input voltage, which comes from the battery 1 or 2 pack. The TL496 operates in a switching regulator, the power loss is less than the typical linear regulator.

Read more source: http://www.eleccircuit.com/micro-dc-converter-3v-to-9v-using-tl496/