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  1. Audioguru

    Modifying a led strip circuit

    Then I am correct. This thing from India is extremely dangerous. Modern LED strings in the West are powered from 12VDC. Deep, is your name from India?
  2. Audioguru

    Modifying a led strip circuit

    Your meter probably cannot measure the short duration blinks, so measure the DC voltage that powers the controller circuit board instead. The controller is probably a black or white blob of plastic on the back of the circuit board that covers the mini-computer chip that creates the blinking...
  3. Audioguru

    Over-voltage protection for op amp

    The input has a maximum current rating because it probably already has a protection diode which has a low current rating. The protection resistor shown in the datasheet does not show an additional diode so why add one?
  4. Audioguru

    Modifying a led strip circuit

    You can design and build a circuit to electronically press the button 7 times each time it is turned on. Or you can trace the wiring of the LEDs then power them separated from the controller circuit. Your photo does not show the circuit (maybe it is a mini-computer) or its program.
  5. Audioguru

    Modifying a led strip circuit

    Do you want a one color LED strip to blink only one blinking pattern continuously? Then you must find or design and build a circuit that will do it.
  6. Audioguru

    USB BATTERY PACK CIRCUIT

    Your two AA batteries in series make 2V to 3V but USB is supposed to be 5V. What are you trying to charge with it? Anything that normally charges from USB needs 5V.
  7. Audioguru

    Meaning of switched jack socket pins

    Pins 4 and 5 are the "disconnected connections". Usually two speakers (stereo) are connected to them and the speakers are disconnected when the headphones plug is inserted. The arrows clearly show that their connection with the "V" (pin 2 or pin 3) is disconnected when a plug is inserted. I...
  8. Audioguru

    Gunn Diode

    If you have the part number then you can look at its datasheet.
  9. Audioguru

    problem sourcing capacitors please help

    Kiss the old amplifier goodbye and bury it. I took big capacitors from a fairly new amplifier that was dropped (not by me) and broken and put them in my very old amplifier that I almost threw away about 10 years ago.
  10. Audioguru

    Over-voltage protection for op amp

    A diode will clamp the input voltage to be higher than the maximum allowed input voltage.
  11. Audioguru

    Mini wind turbine to light an LED

    I smell a home-made PUT!
  12. Audioguru

    Mini wind turbine to light an LED

    Did you measure the voltage from the generator and the voltage of the charged capacitor? If it is 2.5V or more then the red LED should light if the resistor value is correct. What was your resistor value? Here is a simple schematic providing about 10.3mA of current in the LED:
  13. Audioguru

    P channel mosfet

    Your schematic is a backwards negative image that I can barely see. Why not use black lines on a white background like everyone else?? A Mosfet gets hot when its current is high and its gate voltage is not enough. The datasheet for your Mosfet says that with a gate-source voltage of 4.5V then...
  14. Audioguru

    Modifying a led strip circuit

    Como estas, (my wife is from Spain but I don't speak much Spanish). Millions of LED strips are sold on ebay. My local electronics parts store has many LED strips.
  15. Audioguru

    Over-voltage protection for op amp

    Sorry, the 300k resistor value is correct and will not add much noise compared to your very noisy 5M resistor. If an input voltage 0.6V higher than the supply is acceptable then you would think the datasheet would say so. Instead, the datasheet says the absolute maximum allowed input voltage is...
  16. Audioguru

    Over-voltage protection for op amp

    The input current of an AD549 is almost nothing. Your negative feedback resistor value is very high at 5M so an extremely high value protection resistor of 300M (not 300k) is needed which creates a lot of noise.
  17. Audioguru

    HOW TO ID-- A 12 VOLT ZENER DIODE --ONE WATT --

    How on earth can the horrible TIP122 circuit produce an output voltage higher than the 12V zener diode even when it uses an ordinary high input current TIP41 transistor instead of the very low input current TIP122?? Oh, when the "12V" zener diode actually has a much higher voltage or is...
  18. Audioguru

    Modifying a led strip circuit

    If the controller of your LED strip is designed to switch patterns then that is what it will do. If you want an LED strip to make permanent light then buy one that is designed to light permanently.
  19. Audioguru

    Mini wind turbine to light an LED

    A while ago there was a thread where a guy used a computer fan on his bicycle to charge a battery to power night LEDs. The LEDs lighted only for a moment unless he rode the bike very fast all day to charge the battery. If you fully charge your capacitor then how long does the LED light from it?
  20. Audioguru

    Building an adapter - dual quarter-inch and 3.5 mm, to 3.5 mm

    Sorry, you did not say the speakers are amplified and I did not look them up. I thought the audio interface and pc have speaker amplifier outputs to feed the studio monitor speakers you mentioned that must never be shorted together and an 8 ohm speaker fed through a resistor sounds like a bongo...
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