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High Current Step-Up Converter Using MAX641 integrated circuit, manufactured by Maxim IC, can be designed a very simple step-up converter using few electronic components. This step-up high voltage converter electronic projects allows a maximum output current up to 1A. High Current Step-Up Converter Circuit Diagram Low battery voltage detector input compare LB1 with internal reference of 1.31 V. LBO output goes in low state when the voltage at pin 1 falls below 1.31 V. The threshold voltage for "low battery", is determined by voltage divider R1-R2. LED D1 illuminates the LBO output when the input voltage falls below 2.62 V. Input voltage must remain below 5 V. The maximum effectiveness is 80% conversion.

This is a Simple Step-Up Converter For 20 LEDs circuit Project. The circuit described here is a step-up converter to drive 20 LEDs, designed to be used as a home-made ceiling night light for a child’s bedroom. This kind of night light generally consists of a chain of Christmas tree lights with 20 bulbs each consuming 1 W, for a total power of 20 W. Here, in the interests of saving power and extending operating life, we update the idea with this simple circuit using LEDs.  Power can be obtained from an unregulated 12 V mains adaptor, as long as it can deliver at least about 330 mA.  The circuit uses a low-cost current-mode controller type UCC3800N, reconfigured into voltage mode to create a step-up converter with simple compensation. By changing the external components the circuit can easily be modified for other applications. To use a current-mode controller as a voltage-mode controller it is necessary to couple a sawtooth ramp (rising from 0 V to 0.9 V) to the CS (current sen...

This is a 5V to 12V DC-DC step-up (boost) converter circuitry that is especially ideal for the USB powered applications. First of all a USB port has two current supply modes. Before detecting the connected device, it supplies maximum 100mA to the load. After recognizing the device, it increases the output current up to 500mA. In this circuit, controller (LT1618) also provides two input current modes. 100mA and 500mA input modes can be selected by the user. USB 5V to 12V DC-DC Step-Up Converter by LT1618  Output currents are limited due to the increased potential difference at the output. When the demand of the load increases, output voltage will start to decrease. For example, if the circuit operates in the 100 mA input mode, when the load is 35 mA, the output voltage will be kept at 12V. But if the load increases to 50 mA, output voltage will reduce to 8V to maintain the constant 100 mA input current.

The circuit described here is mostly aimed at development engineers who are looking for an economical step-down converter which offers a wide input voltage range. As a rule this type of circuit employs a step-down converter with integrated switching element. However, by using a more discrete solution it is possible to reduce the total cost of the step-down converter, especially when manufacturing in quantity. The TL5001A is a low-cost PWM controller which is ideal for this project. The input voltage range for the step-down converter described here is from 8 V to 30 V, with an output voltage of 5 V and a maximum output current of 1.5 A. When the input voltage is applied the PWM output of IC1 is enabled, taking one end of the voltage divider formed by R1 and R2 to ground potential. The current through the voltage divider will then be at most 25 mA: this value is obtained by dividing the maximum input voltage (30 V) minus the saturation voltage of the output driver (2 V) by the total resi...