3Amps Adjustable Power Supply Provides 1.2V to 15V DC LM1084-ADJ

Simple power supply circuit provides variable output voltage 1.2V to 15V DC and load current up to 3 Amps, onboard trimmer pot provided to adjust the output voltage. Output capacitor C3, C4 provided for transient response, the circuit can take DC input as well as AC input, maximum DC input 15V DC and AC input 12V AC. LM1084-adj IC is heart of the project.

LM1084-ADJ Data Sheet


  • Output 1.2V to 15V DC
  • Input DC 15V DC
  • Input AC 12V AC
  • Load Current Up to 3Amps

Note : The project also can be used with LM1085-ADJ, LM1086-ADJ, AND LM317-ADJ

Note : Higher input and output volatge possible with few changes, input filter capacitor volatge , higher current bridge rectifier can provide higher current up to 5amps with LM1084-adj. refer data sheet of LM1084-ADJ



The LM1084 is a regulator with a maximum dropout of 1.5 V at 5 A of load current. The device has the same pinout as TI’s industry standard LM317.

Two resistors are required to set the output voltage of the adjustable output voltage version of the LM1084. Fixed output voltage versions integrate the adjust resistors.The LM1084 circuit includes a zener trimmed bandgap reference, current limiting, and thermal shutdown.

Refer to LM1085 for the 3A version, and the LM1086 for the 1.5A version.

60V to 5V-2Amps USB Power Output DC-DC Converter for E-Vehicle

Tiny 60V to 5V USB power converter is based on TPS54560 IC, the projects provides 5V DC and peak current up to 5Amps, constant current up to 2Amps. It can be used in lots of application where high voltage to 5V DC USB power required, good use in automotive application. It can be used in E-vehicle for smart phone charger,  USB Hub connector mounted on board for easy connection, input has screw terminal.

Download Data Sheet TPS54560


  • Supply input 9V to 60V DC
  • Output 5V DC
  • Load Current 5 Amps Peak and 2Amps Constant
  • Onboard USB Hub Connector
  • Good for E-Vehicle, Carts, Trucks as for USB Charger

Watch Video Of This Project

High Voltage Low EMI Power Supplies for AC Inverters and VF Drives, Brush-Less Motor Drivers

The high voltage high current low EMI, power supply circuit published here is intend use for AC inverters and VF drives,AC servo driver, brushless dc motor driver, IPM (Intelligent Power Module) , high voltage DC brushed motor drivers and various other circuit required high voltage DC supply.   Capacitor has been selected for AC power input up to 250V AC however capacitor voltage and value can be alter as per DC output required.  Bridge rectifier can handle current up to 25Amps and need large heat sink for full load. Onboard transformer used as EMI fliter.

  • AC Supply input up to 250V V AC
  • Maximum DC Output 400V DC and 10Amps.
  • DC Supply Output will depend on input supply
  • Fuse for Short circuit and over current protection
  • Fuse as per your application requirement Maximum 10Amps Fuse
  • NTC provided for inrush current
  • DC Bus has bleeding resistor








Power Supply for Hi-Fi Audio Amplifier – Symmetrical Output Including +/-15V DC Output

The power supply has been designed to use for audio power amplifiers. This power supply uses a transformer, a bridge rectifier, various rail capacitors, fuse for protection, also supply has separate dual regulators for +/-15 V DC output.  Maximum output for main audio amplifier +/-42V DC, high voltage output possible by altering bus capacitor voltage. The power supply also provides +/-15 V DC to power up pre-amplifier or other support circuit required symmetrical low regulated voltage. Replace LM7815/LM7915 IC with LM7812/LM7912 if need +/-12V regulated output. NTC used for inrush current at power on. All inputs and outputs provided with Screw terminals for easy connections. Project can provide Load current up to 10Amps for amplifier and +/-15V 500mA for pre-amplifier. R2 and R3 resistor used to discharge the capacitor at power off.

Note 1 : Default Bus capacitor value used for 30-0-30V AC Transformer, For higher voltage output use appropriate capacitor voltage. 

Note 2 : Short the EMI transformer T1 terminal using jumper wire as shown in circuit  (Transformer not required for Audio amplifier)

Note 3 : Advisable to use Chassis earth connection, Tie ETH terminal to amplifier chassis


  • AC Input 30-0-30V AC 10Amps Center Tape Transformer
  • AC Input 12-0-12V 500mA
  • +/-42V, 10Amps DC Output ( Unregulated)
  • +/-15V , 500mA DC Output ( Regulated) for Pre-Amplifier and Biasing Circuit











1.2V To 37V, 3Amp Adjustable Power Supply Using LM2576

This regulator board delivers 3Amp current and adjustable voltage range 1.23V to 37V, with input voltage 40 V.The board built around LM2576-ADJ from Texas instruments. A 3.0 A output current capability power supply that features an adjustable output voltage,  In order to achieve a 10 or more times reduction of output ripple. LM2575ADJ IC also can be used in same project if output current requirement is low as 1Amp.LM2576HVT-ADJ IC Can help to provide higher voltage output range 1.2V-50V @ 3Amp current.


  • Output 1.2 to 37 VDC @ 3 A
  • Onboard Trim-Potentiometer for output voltage adjust
  • On Board Power LED
  • Header Connector For Input & Output
  • Adjustable Version Output Voltage Range, 1.23 to 37 V +/-4%
  • Maximum Over Line and Load Conditions
  • Guaranteed 3.0 A Output Current
  • Wide Input Voltage Range 40V
  • 52 kHz Fixed Frequency Internal Oscillator
  • TTL Shutdown Capability, Low Power Standby Mode
  • High Efficiency
  • Thermal Shutdown and Current Limit Protection









Download Data Sheet LM2576ADJ

Download Data Sheet LM2575ADJ


LM2576HVT Based Circuit can provide higher voltage output Range 1.2V to 50V DC , current upto 3Amps



12V To 24V, 1Amp Step Up DC-DC Converter Using LM2588

12V To 24V Booster is based on LM2588-ADJ IC from Texas Instruments. The LM2588-ADJ regulator integrated circuit specifically designed for fly-back, step-up (Boost) , and forward converter. The board provides 24V DC 1A DC output, Input 8V to 16V DC. project  has minimum components, screw terminal provided for input & outputs.

Note : Use LM2588-ADJ IC


  • Supply Input 8V To 16V DC ( Ideal 12V DC)
  • Output 24V 1A










Download LM2588 Data Sheet


12V-SLA Lead Acid Battery Charger Using BQ24450

The project has been developed to charge the SLA (Lead Acid Battery) . The project helps to charge 12V Lead acid battery up to 12Ah, specific current output possible altering the current sense Resistor.  The BQ24450 chip contains all the necessary circuitry to optimally control the charging of valve-regulated lead-acid batteries. The IC controls the charging current as well as the charging voltage to safely and efficiently charge the battery, maximizing battery capacity and life. Depending on the application, the IC can be configured as a simple constant-voltage float charge controller or a dual-voltage float-cum-boost charge controller.

The built-in precision voltage reference is especially temperature-compensated to track the characteristics of lead-acid cells, and maintains optimum charging voltage over an extended temperature range without using any external components. The ICs low current consumption allows for accurate temperature monitoring by minimizing self-heating effects.

The IC can support a wide range of battery capacities and charging currents, limited only by the selection of the external pass transistor. The versatile driver for the external pass transistor supports both NPN and PNP types and provides at least 25mA of base drive.

In addition to the voltage- and current-regulating amplifiers, the IC features comparators that monitor the charging voltage and current. These comparators feed into an internal state machine that sequences the charge cycle. Some of these comparator outputs are made available as status signals at external pins of the IC. These status and control pins can be connected to a processor, or they can be connected up in flexible ways for standalone applications.


  • Input Supply 16V-20V DC
  • Charging Voltage 12V SLA(Lead Acid Battery),AGM
  • Lead Acid Battery 5-12Ah  ( 500mA)



The circuit is to use dual Transistor for current up to 1A-15Amps, use proper transistor as per current requirement.

NOTE : This board has been designed for dual transistor, for load current up to 1Amp use single PNP transistor as such TIP32 TO220, Omit Q2 and use Q1, Transistor pins configuration as shown in bellow picture. Omit R5 and R6 is 0 Ohms.




6V Lead Acid SLA Battery Charger Circuit Using BQ24450

The bq24450 board assists users in evaluating the BQ24450 linear battery charger IC. The User’s guide the bq24450 bill of materials, schematic. The bq24450 contains all the necessary circuitry to optimally control the charging of lead-acid batteries. The IC controls the charging current as well as the charging voltage to safely and efficiently charge the battery, maximizing battery capacity and life. Depending on the application, the IC can be configured as a simple constant-voltage float charge controller or a dual-voltage float-cum-boost charge controller. This 6V Lead Acid Charger circuit from www.ti.com EVM manual

  • Input Supply 9-13V DC
  • Charging Voltage 6V SLA(Lead Acid Battery),AGM
  • Lead Acid Battery 5-12Ah  ( 500mA)

Download : BQ24450 Data Sheet

Circuit Courtesy www.ti.com



Passive PFC Circuit for 250W PC Power Supply

The circuit show here is input circuitry of the power supply with passive PFC. Note the line voltage range switch connected to the center tap of the PFC inductor. In the 230V position (switch Open) both halves of the inductor winding are used and the rectifier functions as a full wave bridge. in the 115V ( switch closed) position only the left half of the inductor and left half of the rectifier bridge are used, placing the circuit in the half wave double mode. As in the case of the full wave rectifier with 230V AC input, this produces 325V DC at the output of the rectifier. This 325 VDC bus is , of course, unregulated and move up and down with i9nput line voltage.

Circuit Courtesy www.onsemi.com


The AC-DC power stage is shown in Figure 6. The connection port is set up identical to the ECM motor controller port for ease of testing. The common is the output port for the control signal 24-V AC inputs. The other input/output ports are for the hot, neutral, and earth ground connections. This TI Design also incorporates a 15-A 250-V AC rated fuse to prevent damage to the board in case of overcurrent. The RV1 metal oxide varistor (MOV), rated for 275-VRMS, is also used for surge protection. Both 499-kO resistors are used as the discharge resistive network for capacitors C5 and C6, and are rated for 400 V. The rectification bridge is rated for 200 V at 35 A, leaving plenty of room for a sufficient safety
factor. L2 is a common-mode filter. To limit the inrush current of the bulk DC capacitors, an inrush current limiter RT1 is provided. D4 is the full bridge rectifier. L1 is the DC choke provided for meeting the line harmonic standard. C7 is the electrolytic capacitor at the DC bus. The AC-DC subsection of the design has been designed with the DC bus capacitor and necessary filters for conducted emission, surge, and EFT protection as per the standard EN55014. Figure 7 shows the simulation output of the design using the listed circuit parameters.To reduce the voltage ripple of the DC output, calculate the bulk capacitor or DC link capacitor value. This helps ensure that a sufficient hold up time is provided, during which the regulated supply continues to provide the regulated voltage output in the event of a short lapse in AC voltage supply. The following arithmetic is used to properly fit the circuit with an appropriately sized DC bus capacitor.



Power Supply For Ultra High-Fidelity Audio Amplifier LME49810, LME49811, LME49830

This application note will cover the design of a ±72V unregulated power supply designed specifically for the LME49810, LME49811 and LME49830 high-fidelity audio amplifier modules. The output power of the modules are approximately 220W to 250W into 8Ω and 350W to 400W into 4Ω. Complete documentation for the amplifier modules can be found in the documents listed below. AN-1625 LME49810TB Ultra-High Fidelity, High-Power Amplifier Reference Design AN-1850 LME49830TB Ultra-High Fidelity, High-Power Amplifier Reference Design Although the power supply design is specific to the amplifier modules the concepts and circuit design may be used for any power supply purpose. The power supply is an unregulated design with an option to allow connection to either 120V or 240V mains. The design uses toroidal transformers, a fully integrated bridge, and various rail capacitors for ripple voltage reduction, noise suppression, and to act as high current reservoirs. Additional circuitry to control inrush current on power up and power up/ down Mute control are also included. A complete schematic, PCB views, and Bill of Materials are provided for the power supply design.

Texas Instrument Applications Down Load



900W PFC Circuit

This PFC circuit is designed using Power Integration’s HiperPFS PFS729EG integrated PFC controller. This design is rated for a continuous output power of 900 W and provides a regulated output voltage of 380 VDC nominal maintaining a high input power factor and overall efficiency from light load to full load.

4.1 Input EMI Filtering and Rectifier

Fuse F1 provides protection to the circuit and isolates it from the AC supply in case of a fault. Diode bridge BR1 rectifies the AC input. Capacitors C1, C2, C3, and C4 together with inductors L1, L2 and L3 form the EMI filter reducing the common mode and differential mode noise. Resistors R1, R2 and CAPZero, IC U1 are required to discharge the EMI filter capacitors once the circuit is disconnected. High frequency decoupling capacitor C5 after the bridge reduces the loop area of the high frequency loop and helps reduce the noise coupled into the input wires. Resistor R3 connected in series with capacitor C1 provides damping. Metal Oxide Varistor RV1 is placed across AC power lines to provide differential mode surge protection.

4.2 PFS729EG Boost Converter

The boost converter stage consists of inductor L4, diode rectifier D2 and the PFS729EG IC U2. This converter stage works as a variable frequency continuous conduction mode boost converter and controls the input current of the power supply while simultaneously regulating the output DC voltage. Diode D1 prevents a resonant buildup of output voltage at start-up by bypassing inductor L4 while simultaneously charging output capacitor C13. Thermistor RT1 limits the inrush current of the circuit at start-up. In higher performance (efficiency) power supplies, this thermistor is shorted after start-up using a relay. Efficiency measurements should therefore be taken with RT1 shorted to obtain maximumefficiency data. Capacitors C11 and C12 are used for reducing the loop length and area of the output circuit to reduce EMI and overshoot of the voltage across the drain and source of the MOSFET inside U2 at each switching instant.

4.3 Bias Supply Regulator

The PFS729EG IC requires a regulated supply of 12 V for operation. Should this supply exceed 13.4 V, the IC could be damaged. Resistors R7, R8, R9, Zener diode VR1, and transistor Q1 form a shunt regulator that prevents the supply voltage to IC U2 from exceeding 12 V. Capacitors C6, C7 and C8 filter the supply voltage to ensure reliable operation of IC U2. Diode D3 protects the circuit against accidental reversal of polarity of the bias supply.

4.4 Input Feed Forward Sense Circuit

The input voltage of the power supply is sensed by the IC U2 using resistors R4, R5 and R6. The capacitor C9 filters any noise on this signal.


Circuit From www.powerint.com

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