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  1. audioguru2

    Why Circuit not outputting max voltage?

    I explained your problems a few minutes ago on another website forum: 1) No schematic. 2) I do not know the maximum current of the motor. 3) The first breadboard photo shows an L293 driver. Look at its high voltage loss in its datasheet. 4) The second breadboard photo shows an IRF540 Mosfet. Its...
  2. audioguru2

    9v Car port?!

    What is "a red light equalizer"? A red bar graph display of sound levels? Did you look at the datasheet of a 9V alkaline battery to see how little is its amount of power? It can light one LED brightly at 25mA for about 18 hours then it dims for another 18 hours until it is invisible. If a red...
  3. audioguru2

    circuit diagram needed.

    It looks like a power supply for a computer. There are hundreds of circuits linked in Google.
  4. audioguru2

    Transistor Conection

    Why don't you look up its datasheet? It is not a bipolar transistor. It is an IC with a Cmos driver and a power Mosfet. It is made by Panasonic. I found its datasheet at www.datasheetarchive.com .
  5. audioguru2

    high frequency audio amplifiers

    Audio opamps are low noise, have very low distortion and perform very well up to about 100kHz. We do not know if you are making a preamp or a power amp.
  6. audioguru2

    28volt power supply

    Burn down your house with this simple circuit that will have excellent voltage regulation:
  7. audioguru2

    28volt power supply

    I am surprised you didn't fix it. It will be easy to make it work much better with fewer parts, as I explained. Will it burn down your house when it is overloaded?
  8. audioguru2

    28volt power supply

    Why don't you fix it?
  9. audioguru2

    28volt power supply

    Your 1-25volt power supply design is exactly the same as this 28V one with the same problems.
  10. audioguru2

    N00b help for 555 type timer circuit to drive IR LED's

    1A is way too much current. It is its absolute maximum NON-RECURRING (occasionally) pulse just before it blows up. Even 500mA is way too high but might be used for the very short duration pulses in a TV remote control. You forgot to say what you need such high power IR for. Like all LEDs the...
  11. audioguru2

    0-30V Stabilized Power Supply

    Yes, you can use a TL431 voltage reference instead. C5 is a high frequency filter for the supply voltage for the output amplifier that helps to prevent oscillations at high frequencies.
  12. audioguru2

    0-30V Stabilized Power Supply

    The 5.6V zener diode has very good voltage regulation (lower and higher voltage zener diodes are worse) and has zero voltage change when the temperature changes unlike other zener diode voltages. The opamp U1 that feeds this zener diode is a current source for even better voltage regulation...
  13. audioguru2

    Replacing li-po with li-ion battery on small device?

    All rechargeable batteries have a capacity rating in mAh (milliamp-hours). Lithium is a dangerous flammable metal (burns white hot like magnesium flares) and catches on fire if a battery is over-charged or is charged when discharged too low. Some rechargeable Lithium batteries have a protection...
  14. audioguru2

    28volt power supply

    Kevin, 1) As I said before, a high voltage zener diode (yours is 28V) has poor voltage regulation and its voltage increases as it heats up. If the input is exactly 30.0V then the 10 ohm resistor feeding the zener diode has a VERY high current of 2V/10 ohms= 200mA (minus 23mA in the pots). Then...
  15. audioguru2

    1-25volt variable power supply

    The output of an opamp is class-AB push-pull so it does not need a load resistor. Where is your schematic and parts list?
  16. audioguru2

    Sending images through transmitters

    Make a TV transmitter?
  17. audioguru2

    0-30V Stabilized Power Supply

    The entire output current flows through the output transistors and their emitter resistors. Since they have a high voltage across them when the output voltage is low or is shorted then they get very hot when the output current is 5A then they need good heatsinking. The MC34071 is not available...
  18. audioguru2

    0-30V Stabilized Power Supply

    Kevin, you are completely WRONG! 1) The output voltage has only a slight effect on the differential input voltage of opamp U2. It increases slightly, it is not eliminated at higher output voltages because U2 is an amplifier. 2) The power supply voltage has no effect on the input differential...
  19. audioguru2

    0-30V Stabilized Power Supply

    Kevin, Didn't you learn anything about opamps? U2 has a DC gain of 200,000 times. If one input is +2.0V then the other input is +2.000005V and the differential voltage is 0.000005V (almost none). The negative feedback sets the gain of the entire amplifier to 2.7 times. What resistance is low...
  20. audioguru2

    0-30V Stabilized Power Supply

    5A in R7 that is 0.27 ohms= 1.35V. 5A/3= 1.67A x 0.33 ohms (the emitter resistors for the three output transistors)= 0.55V. Yes. It is safer not to operate the transistor silicon chip that is inside the case of the transistor at its absolute maximum temperature. Some manufacturers say so on...
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