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  1. Audioguru

    Audio Circuit too sensitive

    I have a cheap clock radio and a Sony Walkman radio that have volume controls with intermittent levels when adjusted. I suspect the crimp between the ground terminal and the resistive track makes a poor connection. When the volume is turned down a little then it goes to full blast.
  2. Audioguru

    How to limit solar current input for testing

    A battery is usually charged with a charger circuit that limits the current.
  3. Audioguru

    How to limit solar current input for testing

    We said the same things at exactly the same time.
  4. Audioguru

    How to limit solar current input for testing

    The ebay ad has hardly any details. The converter steps down a high voltage to 5V or 12V at 250mA max. It does not say what its input current will be but the input power will probably be the output power plus a little more. If the solar panel produces 70V and the 12V output from the converter...
  5. Audioguru

    LED Sequensing or chasing

    The e-project4u.blogspot.com link in post #2 stole my 6V Chaser project using higher voltage coloured LEDs from my project I posted at www.electronics-lab.com . At electronics-lab I also posted a 3V Chaser project using low voltage red LEDs. Two or four AA alkaline battery cells power them...
  6. Audioguru

    LED project.

    I recently made a "flowing" LED sequencer using a CD4017 IC and a resistor, diode, capacitor and transistor on each output. The original article said the LEDs look like "Comet Trails" that slowly fade as the sequencing moves from LED to LED.
  7. Audioguru

    LED Sequensing or chasing

    I make bright chasers with the high speed Cmos iC the 74HC4017. Its maximum allowed output current is 25mA and it works with a supply from 3V to 6V. If LEDs are connected in parallel then they must have matched forward voltages or else the one with the lowest voltage will hog all the current...
  8. Audioguru

    LED project.

    A Knight rider is made with one or two CD4017 (low current) or 74HC4017 (much higher current) sequencer ICs and some diode OR gates. Another 4017 IC can turn the first LED on and off 3 times with OR gates. Each 4017 has 10 outputs (you didn't say how many LEDs) and are clocked with an oscillator...
  9. Audioguru

    Headset

    A mic with a frequency response of 100Hz to 10kHz and headphones to have a frequency response of 20Hz to 20kHz are meaningless unless you specify the level range. There might be huge peaks in the level causing a boomy bass and shrieking highs. The midrange might have a very low level. Or the...
  10. Audioguru

    Volume controller

    It is probably a stereo volume control with 3 pins for each channel. The 7th pin is probably its metal case that you can connect to the circuit's 0V as a shield. Alibaba, Aliexpress and ebay sell CCC.(Cheap Chinese Crap).
  11. Audioguru

    Linear Actuator Power Requirement

    ebay and the seller do not have a clue about how much current the acuator uses. They just know how much profit they get when they sell one. A Duracell MN21 alkaline battery is rated at only 50mAh. The actuator might need 100 or more of those tiny batteries to operate one time.
  12. Audioguru

    Soldering iron trouble.

    Nearly every crimped wire join I have seen let go of the wires with a gentle tug. With all my might I cannot pull apart my soldered connections.
  13. Audioguru

    Inverter Modifications

    The datasheet of the 555 and the SG tells you all about them. Your modified inverter output voltage will be too high when the load is light and will be too low when the load is heavy because it is missing voltage regulation. The heatsinks on the Mosfets are small so the Mosfets will melt if the...
  14. Audioguru

    peak detector design

    The duration of your peak detector is much too long for it to detect the return pulse. Shorten the duration by reducing the value of R1 to 47k or less. Then it will show the transmitted pulse, zero then the return pulse.
  15. Audioguru

    help please about equivalent transistor

    The "A" transistor has low gain and might fail when replacing the "B" transistor that has at least double the gain. A BC546B transistor will make a good replacement.
  16. Audioguru

    Can I re-use old components?

    Did you see what this guy found inside a Chinese 18650 Lithium battery cell? Rice flour and a tiny little Li-Po battery cell.
  17. Audioguru

    LED VU/PPM-meters -metering scales and their use

    You want the input levels to be high enough that the circuit noise is not heard and you want the input levels to be low enough that there is no overload distortion. The VU meter will show you how high and how low the levels are and if they should be increased or decreased. You calibrate the VU...
  18. Audioguru

    why is this comparator triggering on falling edge?

    You are wasting our time by entering the wrong part number and asking why it does something odd. Don't you read the datasheets for the parts you use? The LM324 is completely different to the TL084 but the case and pin numbers are the same. I think all quad opamps use this case and pin numbers...
  19. Audioguru

    why is this comparator triggering on falling edge?

    The datasheet of the old LM324 and LM358 says, "Either or both inputs can go to +32V without damage (+26V for LM2902), independent of the magnitude of V+".
  20. Audioguru

    Can I re-use old components?

    I have a set or 480 carbon film 1/4W 5% resistors from Velleman (Belgian)?). The resistors have colors where blue and green, orange and red and yellow and brown are almost the same. The leads are thin and flimsy. Most have accurate values but some do not. They are made in China and have too much...
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