LT3760 8-channel LED driver circuit.

This Led driver circuit schematic is based on the LT3760 8-channel LED driver circuit which is a step-up DC/DC controller capable of driving up to 45V of LEDs.
Each channel of LT3760 contains an accurate current sink with ±2% current matching. Output current for each channel can be programmed from 20mA to 100mA per string but for higher output LED current the channels can be paralleled .

Micropower DC-DC Converter circuits LT1073

 Features

• No Design Required
• Operates at Supply Voltages From 1.0V to 30V
• Consumes Only 95µA Supply Current
• Works in Step-Up or Step-Down Mode
• Only Three External Off-the-Shelf Components Required
• Low-Battery Detector Comparator On-Chip
• User-Adjustable Current Limit
• Internal 1A Power Switch
• Fixed or Adjustable Output Voltage Versions
• Space-Saving 8-Pin MiniDIP or SO8 Packag

Typical Application

Description

The LT1073 is a versatile micropower DC/DC converter. The device requires only three external components to deliver a fixed output of 5V or 12V. The very low minimum supply voltage of 1V allows the use of the LT1073 in applications where the primary power source is a single cell. An on-chip auxiliary gain block can function as a low-battery detector or linear post-regulator. Average current drain of the LT1073-5 used as shown in the Typical Application circuit below is just 135µA unloaded, making it ideal for applications where long battery life is important. The circuit shown can deliver 5V at 40mA from an input as low as 1.25V and 5V at 10mA from a 1V input.
The device can easily be configured as a step-up or step-down converter, although for most step-down applications or input sources greater than 3V, the LT1173 is recommended. Switch current limiting is user-adjustable by adding a single external resistor. Unique reverse-battery protection circuitry limits reverse current to safe, nondestructive levels at reverse supply voltages up to 1.6V.

Applications

• Pagers
• Cameras
• Single-Cell to 5V Converters
• Battery Backup Supplies
• Laptop and Palmtop Computers
• Cellular Telephones
• Portable Instruments
• 4mA-20mA Loop Powered Instruments
• Hand-Held Inventory Computers
• Battery-Powered Alpha, Beta and Gamma Particle Detectors

Electronics Circuit Application

3Vdc to 12Vdc step up DC converte circuits.

The 3Vdc to 12Vdc step up DC converter by IC LT1073-12,

2X50 W TDA1562 stereo AMP circuits

4AA Battery Powered 12V LED Spotlight - 12V Power Supply circuits

Most of the electronic projects and electronic devices are required 12V power source; typically a 12V sealed lead acid battery or AC powered power supply. These are typically large, heavy, difficult to handle, and expensive; portability is less. The best solution is to use a DC-DC Step up converter. These types of convertors are inexpensive, light weight and easy to use. Also provides power management and easy to work with renewable energy sources.

The input power source could be rechargeable AA batteries. Let’s make an environment friendly 12V/130mA power supply!

 

 100uf Electrolytic Capacitor 16V C1,C2 -2
100Ohms Resistor 1/4W R1,R2 -2
1N5817 Schotkey Diode 1A D1- 1
150UH Radial Power Inductor 1A IND1- 1
LT1073CN8-12 IC DIP Package IC1 -1
IC Base 8 PIN -1
PCB to Wire Connector- 2
4AA Battery Holder- 1

The heart of this application is LT1073 IC. It is a power management IC which steps up low voltage into high voltage by switching.

First I etched four PCBs for the prototype using a PCB design software and some other tools. The PCBs are very small (4cmX2cm) because components need to be solder as close as to the IC; because of the performance issues. I made ground copper track as wide as possible.

Now my prototype works fine and I decided to make the PCB in large quantity. I did some changes and sent my PCB file to a local PCB production company and first I got 100 pieces of PCBs. The PCBs are in good quality with solder spots and copper shield; easy to solder

Ratings:
Operating Hours: 20,000 hours
Operating Voltage: 12V
Intensity: 55,000 mcd
Forward Current: 80 mA @ 12Vdc
Viewing Angle: 30 Degrees

Absolute Maximum Ratings:
Operating Voltage(V): 14 V
Operating Temperature (Topr): -25oC to +85oC
Storage Temperature (Ts): -35oC to +100oC

variable voltage adjustable power supply circuits

Features:
Regulated Adjustable Voltage out 2-30VDC
High Current Output 5A (based on transformer selection).
Adjustable Current Limit
Can be used as a variable current supply.
Based on LM317 Voltage Regulator.
Built in protection diodes
Speed controlled fan connection (based on current draw).
Current meter connection (0.1V/1A).

                                                           Circuit Diagram

Features universal capcitor mounting/spacing to allow various capacitors to fit.  Mounting pattern that fits TO-200 or TO-218/247 for pass transistor and transistor used for current limit circuit.  Fan connection uses connection compatible with standard PC fan connection; allowing use of PC heatsink fan combination.

Circuit Board Layout
Electronics Circuit Application 

MOBILE PHONE BATTERY CHARGER CIRCUITS.

Mobile phone chargers available in the market are quite expensive. The circuit presented here comes as a low-cost alternative to charge mobile telephones/battery packs with a rating of 7.2 volts, such as Nokia 6110/6150.