Search results

  1. audioguru2

    4017 Problem

    No, A 4011 has NAND gates. You need a 4081 or 74C08 which have AND gates, and you would still need an oscillator. I've never tried making a Wien-bridge oscillator from an AND gate or non-inverting buffer, it might work since they have lotsa gain. ;D
  2. audioguru2

    Volt regulator & Battery

    MC34071 opamp.
  3. audioguru2

    Mosfet Latching

    The slow, old 741 produces triangle-waves above 9kHz at high output levels, and although you can't hear its 3rd harmonics beginning at about 27kHz, they cause intermodulation with some real harmonics producing artifacts that are audible. So a loud cymbals beat will sound something like a glass...
  4. audioguru2

    4017 Problem

    Bill Bowden recently posted this 18-stage sequencer on his site. It is complete with all the good stuff like power-up reset:
  5. audioguru2

    Mosfet Latching

    Hi Kiwi, You don't show what the PNP transistor is doing. The old 741 opamp isn't any good above about 9kHz. A TL071 or TL081 and many new opamps are good for up to 100kHz.
  6. audioguru2

    Mosfet Latching

    A 2N2222 or any other silicon transistor makes a pretty good 7V zener diode when its collector and emitter are reversed, doesn't it? Therefore the gate couldn't go lower than 5V. ;D
  7. audioguru2

    Mosfet Latching

    You have a faulty Mosfet. Maybe you zapped its gate. :'(
  8. audioguru2

    Volt regulator & Battery

    Hi Steve, It was difficult to spot the Vref in the datasheet but it is 1.25V just like an LM317. Therefore the resistor to ground is 1032 ohms for a 12V output. The max dropout of an LD1085 is 1.5V at 3A, or 1V at 2A. Your 11 cells will have a voltage of about 13.2V so the regulator just barely...
  9. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Stanley, I'm glad you fixed your problem. I had a quick look at your schematic, but it is difficult to compare with other schematics because you changed all the parts numbers. I think your output will be full of ripple at high current and with voltage settings more than about 25V, because...
  10. audioguru2

    4017 Problem

    It is done like this:
  11. audioguru2

    Mosfet Latching

    Hi Hi Kiwi, You shouldn't just "remove" a gate signal to turn-off a Mosfet, you should leave the resistor from its gate to its source. Mosfets have a fairly high capacitance from gate to source that can hold a charge for a long time without a discharge path. So of course they will be on. ;D...
  12. audioguru2

    Amplified Ear help!!!!

    Hi Ticklebang, ;D Easy, just join them like this:
  13. audioguru2

    12 volt battery charger

    Quote: "So we can say that ANTE is a good person" Hip, hip Horray!                        Hip, hip Horray!
  14. audioguru2

    Regulator Datasheet Parameters meaning!

    Hi Shahriar, The LM317 has a voltage reference and changes to it are amplified by how much higher than its reference voltage is its output voltage. Therefore the conditions for the ripple spec's are with an output voltage of 10V. The output ripple will be lower with a lower output voltage and...
  15. audioguru2

    ACHIEVE LOW ESR CAPACITORS...

    No, The capacitor's ESR is in series with its impedance (capacitive reactance) at a certain frequency. To be a good power supply filter the phase shift of the capacitor would be very low.
  16. audioguru2

    ACHIEVE LOW ESR CAPACITORS...

    Hi Kain, A switching power supply needs an output filter cap with a low ESR so that it can charge quickly by a high current and supply a high discharge current into a load. With the high currents, an ordinary cap would get hot and explode! Adding smaller caps in parallel with an ordinary large...
  17. audioguru2

    Re: Alun's low voltage alarm

    Thanks Alun, Horray! They still make the strong-output LM311. It has about 10 times the wimpy output current of a low-power LM339. ;D
  18. audioguru2

    Hard dsk motor

    I like the Stair Lights. The cat seems to be wondering how the light turn on by themselves. I better not let my wifey see the video or I'll be working on my stairs for weeks. ;D
  19. audioguru2

    Convert 0-30V 3A PSU to 5A or more

    Hi Kain, Be careful with your transformer because it is rated for only (!) 210VA. Its peak current is normally about 50A into the rectifier bridge to replenish the charge lost in the main filter cap during high loading but its average power rating is still 210W. The rectifier conducts only near...
  20. audioguru2

    missing some basic theory

    Hi New Dude, Neither voltage nor current goes in circles in a parallel circuit. In your schematic, both resistors have the same voltage. The current in each one is determined by Ohm's Law (I= E/R). Their resistance in parallel Rp is also determined by Ohm's Law when you add their current into It...
Top