Search results

  1. obiwan

    Lt1242 very simple ltspice simulation not working please help

    Hi all, I am trying to understand why this simulation on LTSpice of an LT1242 which is a replacement for the UC3842 is not working. The test consists to apply a linear voltage ramp to the COMP pin to see if the output produces a PWM signal with a variable duty cycle. It seems to switch directly...
  2. obiwan

    NEED HELP UNDERSTANDING SOA IN SWITCH MODE MOSFET's

    For a very specific application, a 100V @ 10 A power supply is needed. As galvanic isolation is not a requirement and 400V DC is available at the final destination location. My first experiment was to build a buck converter. I calculated the filter, made a ring core inductor. I used an old...
  3. obiwan

    Help determine mu permeability e core w/ simple method l/c sine generator + scope

    Hello friends ! I have many different E , EI , ER, R cores from different manufacturers I bought sometime. These cores are kept grouped in the same bags and boxes the day I bought them, so no mix up possible. But they don't have any inscription, code, part no. , model, etc. I need to determine...
  4. obiwan

    TWO MOSFETs FORWARD CONVERTER - NEED HELP PLEASE

    Hi, I am trying to build a 60 Watt SMPS using this topology: I am using this transformer design tool: http://www.diysmps.com/forums/showthread.php?522-Calculation-programs-for-transformers-and-inductors My question: for the calculation of the transformer, is this a Half or a Full bridge...
  5. obiwan

    Help please with glitch in an half bridge inverter

    Dear friends, could you please help me solve this glitch in my inverter ? Here is the output circuit and oscillograms. Attached pictures: - A and B signals at de gates - C output signal - Schematic diagram The transformer calculation done with Dimitri's program, output voltage and current are...
  6. obiwan

    How to connect multiple power suplies outputs in parallel

    Hello ! I guess how many SMPS could be tied together to obtain high currents, e.g: 24 V @ 12 kW from several 1 kW devices, to a single resistive load. Could this be possible ? How to equalize the several individual power supplies ? Is there a simple method ? Thank you. Obiwan
  7. obiwan

    How to power up a smps for the first time

    Hello friends. I am new, and although I have experience in electronics, I am quite ignorant about SMPS and I am starting from scratch. So any wise suggestions are going to be very welcome. I decided to start a project. I thought the simplest was using PI Expert software from Power Integrations...
Top