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  1. Silvio

    Ir2153 oscillation problem

    The high side gate drive pin7 gets its power from the bootstrap capacitor. This capacitor charges itself when the lowside mosfet comes on. You will not see an output voltage on pin7 without mosfets. To make an smps you need at least a frequency meter. An oscilloscope is essential as you cannot...
  2. Silvio

    Help Pls: IR2153 HB failure.

    One other thing I am noticing is that the voltage regulation at pin 1 is all depending on the internal 15v zener inside the chip. I also advise you to add an external 15v zener from pin 1 to pin 4 to help out with current handling. This 18K resistor feeding pin 1 deliver a power of around 650mW...
  3. Silvio

    Help Pls: IR2153 HB failure.

    The IR2153 is designed to power medium power mosfets, (10A) however in this circuit the 20n60 mosfets used have a a very low gate charge (170nC) the chip can drive them well. If you are using different ones then observe the datasheet and note the total gate charge. This must not exceed 200nC...
  4. Silvio

    Testing circuits

    First of all if you intend to build a high current smps, then it has to be prepaired from the design stage. Type of transformer, frequency, voltage, and last but not least type of switching transistors, diodes etc. The bread board or vero board is not siutable to test high currents on it. As...
  5. Silvio

    Help Pls: IR2153 HB failure.

    Do you have a problem maybe I can help you? Regards, Silvio
  6. Silvio

    Making litz wire at home

    Well I also tried my software Excellent IT 7300 at this but as you can see the rated transformer power is far less the the desired output power. The trafo rated power is 175w while your desired output power is 280w!! The software is telling me that the winding fill factor is also larger then...
  7. Silvio

    The 100k resistor initially charges up the 2 capacitors 100uf until the SG chip starts to...

    The 100k resistor initially charges up the 2 capacitors 100uf until the SG chip starts to oscillate, the auxiliary winding will then generate the voltage needed to power the auxiliary supply. The voltage at the auxiliary supply is held constant and regulated by the zener diode and the...
  8. Silvio

    Best heat transfer insulator

    Thanks for your reply, I also taught that ceramic had to be the best in this case thus having also the best insulating properties. The only mishap with them is that they need perfectly flat and clean surface as they break easily when tightened up. I usually sand the back of transistors with a...
  9. Silvio

    Best heat transfer insulator

    Seeing a lot of commercial amplifiers, I find various types used. In good quality amplifiers like Herman kardon use mostly ceramic in class d amplifiers and where high voltage is present, other Chinese stuff you will probably find mica or silpads. My true question was which of these has the...
  10. Silvio

    Two switch forward based on UC3845

    Do you have headroom voltage to regulate the output? You cannot sustain the output with load without headroom voltage to spare. It is quite obvious that the output is dropping as you did not use regulation. Your output is showing the maximum voltage the smps can give. Without regulation the...
  11. Silvio

    IR2153 SMPS TEST

    130 khz is rather a high frequency and there tend to be a lot of switching losses. These losses generate heat at high frequency. Working out the number of primary turns you are a bit over at 40 turns primary. At 100khz this would be somewhat close to the number of primary turns you have on the...
  12. Silvio

    IR2153 SMPS TEST

    Post the full schematic. I am not sure but trying to peep further on to the output side i think there is an opto which will regulate the output voltage. The IR2153 is not meant to be regulated. Using an SG3525 followed by a GDT will do a better job if the output needs to be regulated. The...
  13. Silvio

    900w +-70v half-bridge smps

    The smps you are showing here was published on however I am giving the link for you to see the finished product Regards Silvio
  14. Silvio

    Switching power supply design by Abraham L Pressman

    I have it somewhere buried in my old laptop. I will send it to you as soon as I find it.
  15. Silvio

    Audio smps 700w (IR2153)

    1) I cannot see the soft start resistor. The triac mt1 and mt2 terminals should be across it. 2) you only need 1 bridge rectifier at this power, no need for 2. 3) the 15v regulators need heatsink and also the triac at the input. If this is the revision 2 version i see you built the one with...
  16. Silvio

    1000w smps based on LUDO3232

    Yes it is
  17. Silvio

    1000w smps based on LUDO3232

    Here is the final PDF of the 1000w smps. This contains also options for feedback but if you intend to use it for audio purpose then you can omit this feature. I found it works better with less noise. I can drive my 1000w amplifier very well. You can find the amplifier using this smps in the...
  18. Silvio

    1000w smps based on LUDO3232

    Yes you can use the 0.45 mm wire instead it is still good. You can use 2 bundles of 5 wires each 0.45 mm. This will give you a cross sectional area of 1.59mm^2 which is about the same. However an EE55 core is slightly bigger than ETD49. My final number of turns with ETD49 was 18 turns primary...
  19. Silvio

    IR2153 Soft Start

    Well the attachment is related to snubbers. This will depend on 1) the leakage inductance of the trafo, 2) if the secondary winding has an inductor after the diode. 3) pcb design. These are the main causes of spike generation and also the need for a snubber. An smps running with a 50% pwm duty...