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  1. audioguru2

    0-30V Stabilized Power Supply

    Your unloaded supply is 46V which is 2V higher than the 44V absolute max supply for the opamps. Try reducing it with 5.1V or 5.6V zener diodes to see if the output will be 30V with a current of 3A.
  2. audioguru2

    0-30V Stabilized Power Supply

    Power is measaured in Watts. Power is volts multiplied by amps. The volts for a 4.7V zener diode is 4.7V and some of the current can be found on the datasheet for the opamps which is 4.5mA max. Each opamp has a load current of 5.5mA so the total current in each zener diode is 10mA. Then the...
  3. audioguru2

    0-30V Stabilized Power Supply

    No. Pin 7 is the positive power supply pin. You have the zener diodes on an input pin instead which is wrong. The cathode of the zener diode connects to the positive supply and the anode connects to pin 7 of an opamp.
  4. audioguru2

    0-30V Stabilized Power Supply

    The opamp U3 on my schematic and the transistor that drives the LED already have a 10V zener diode in series with their positive supply because the max output of U3 is only 28V to 30V.
  5. audioguru2

    0-30V Stabilized Power Supply

    Simple arithmatic shows that the unregulated voltage will be 46V which is too high since the absolute max voltage for the TLE2141 or MC34071 opamps is 44V. Reduce the 46V to 41.3V with a 4.7V zener diode in series with the positive supply pin of my U1 and U2.
  6. audioguru2

    0-30V Stabilized Power Supply

    The driver transistor is supposed to be a high frequency BD139, not a low frequency TIP3055 for good transient response. In an opamp circuit that has negative feedback and no output clipping, both inputs have the same voltage. No, it is 0.6V to 1.5V depending on the current. I think beause you...
  7. audioguru2

    0-30V Stabilized Power Supply

    I think PicMaster changed all the parts designation numbers so we don't know which opamp is U1. Please post the schematic you used. If the emitter and collector of the driver or output transistor are wired backwards then the emitter-base becomes a 7V zener diode preventing the output of the...
  8. audioguru2

    0-30V Stabilized Power Supply

    Does your SIM program see parts smoking or failing that are overloaded? Does it know about the electrolytic absorption in the electrolytic output capacitor that causes the output voltage to rise when there is no load? Does it know about the input offset voltages of opamps? Does it know that each...
  9. audioguru2

    how to build a quality inverter

    You forgot to tell us what you need help with. In the first year you should know Ohm's Law, how to calculate power (heating) and know how a transistor works. You should be able to design a simple one transistor common-emitter amplifier. You should be able to design a simple 3 or 4 transistors...
  10. audioguru2

    0-30V Stabilized Power Supply

    There is a Yahoo users group where they make models for any part I don't know why you are simulating this simple power supply, I don't know what you havew a "phase delay" and I don't know why its voltage is wrong. Simply build it and measure it.
  11. audioguru2

    Step Up Battery Voltage Problem

    Didn't you look at the datasheet of the MAX1709? Its max output voltage is only 5V, not 12V.
  12. audioguru2

    0-30V Stabilized Power Supply

    You said you used the SIM program called Protues, not Proteus. Most of us use the newer SIM program called LTspice IV.
  13. audioguru2

    0-30V Stabilized Power Supply

    There are hundreds of SIM programs. I never heard about yours.
  14. audioguru2

    0-30V Stabilized Power Supply

    I am in North America where any part is available. I don't know what is available for you so you should make whatever you can find parts for.
  15. audioguru2

    0-30V Stabilized Power Supply

    The old and simple LM723 regulator circuit needs a 6.8k resistor to ground at the base of the output transistor. It does not have variable current regulation, it has only fixed current limiting that varies a little when the chip tyemperature changes. Its minimum output is 3V, not 0V.
  16. audioguru2

    0-30V Stabilized Power Supply

    If you add another output transistor to the output of an old LM723 regulator IC then each one needs its own 0.33 ohm emitter resistor like is used in the 0V to 30V, 3A project. The emitter resistors for the output transistors will reduce the max output voltage by about 0.33V.
  17. audioguru2

    0-30 Vdc Stabilized Power Supply

    The driver and output transistors are simple emitter-followers so their output voltage should be 1.2V to 2V less than the voltage at the output pin 6 of U2. Since your output voltage is much too low then either your transistors are connected backwards or they are blown up. The collectors of the...
  18. audioguru2

    Step Up Battery Voltage Problem

    No. Your output current is much too high and your input voltage is too low. Select a more powerful stepup regulator that works with your low input voltage.
  19. audioguru2

    Step Up Battery Voltage Problem

    But its max allowed load is 800mA so you overloaded it. Reduce the load current to 800mA then it should work well.
  20. audioguru2

    3v led chaser

    You need to go to school and learn about basic electronic circuits like are used in my project. Then you will know what each resistor, each capacitor and the transistor is for. I don't think anybody here is going to spend a couple of years teaching the basics to you.
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