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  1. audioguru2

    Circuit Help

    Hi Indulis, I haven't seen an LED that performs as poorly as the Vishay TLLR5401 for many years. The Fairchild MV8141 red LED that I use is 10 times brighter, has a wider viewing angle and can be 57 times brighter at its max continuous current. They are both diffused and the Fairchild LED costs...
  2. audioguru2

    6V LED Chaser Question

  3. audioguru2

    Circuit Help

    The Vishay low-current LED is very dim by today's standards. Any fairly modern LED would be brighter and have a wider angle at its low current. At 20mA, a modern LED would be much brighter.
  4. audioguru2

    Negative Voltage Rail Sag

    Hi Mr. Heckles, The absolute value amps will operate the same but now their supply current will be lower. The TCA0372DP1 is a nice one and will work fine with a voltage reference which could even be a zener diode if you want.
  5. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi One Eye, This is a fairly complicated variable voltage and variable current well-regulated supply. You don't need regulation for your driller. Do you need its voltage to be adjustable to control its speed?
  6. audioguru2

    i need help extending the keys finder project. can someone help me out????

    We can't teach you about opamps, your professor should teach you. Post the voltage readings of the CD4069 circuit and we will fix it.
  7. audioguru2

    Circuit Help

    The schematic was a HUGE fuzzy JPG. I shrunk it and posted it as a clear PNG but had to start with the fuzz. It should look better on this page. The 22M pot is backwards and if set to max, the bias current of the LM3914 across it would show a reading of half-scale or more without a signal. A 1M...
  8. audioguru2

    Need Help Alligning IR lasers

    A video camera sees IR. Technicians use a plate of something that glows with IR.
  9. audioguru2

    Transistor ?

    Hi Staigen, My answers covered all the bases (and collectors) including the trap. A transistor doesn't saturate very well with only the tiny base current that is calculated by its beta. ;D
  10. audioguru2

    6V LED Chaser Question

    Hi Giroup, Welcome to our forum. ;D I designed the Chasers and have made many of them. They all perform the same. I have highlighted in red the parts substitutions to be used with a 3V supply and orange or red LEDs. I built many like that. Your NTE substitute might be different from the...
  11. audioguru2

    0-30 Vdc Stabilized Power Supply

    Horray! Mix's project is a success. ;D  Congratulations Mix. But he said it went up in smoke a few times. So I mentioned the other problems everyone else is having with the original project.
  12. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Thomas, Thanks. I am glad that you agree with Staigen and me. Your two 2N3055s burned down probably because your heatsink was too small or because you used insulators. Without insulators, the transistors have much better contact with the heatsink. Then the heatsink must be insulated from the...
  13. audioguru2

    Negative Voltage Rail Sag

    How can they rip you off so much and why do people there let them? If you have a friend in the US who could mail one to you, the postage wouldn't cost very much and delivery wouldn't be long. If you reduce the current of the 4558 opamps by increasing the values of their feedback resistors and...
  14. audioguru2

    Negative Voltage Rail Sag

    Correct. Then you scale the -9V to match it. An LM10CN costs $2.70US, about a cup of coffee in a restaurant. It does everything you need in an 8-pin DIL package. No. The Cmos opamp's output current is way too low. With a 20mA load, its loss is 5V. The opamp's output powers the ICL7660. Your...
  15. audioguru2

    Transistor ?

  16. audioguru2

    quick question

    It isn't complicated. It is a digital switch like you want but it has three of them inside. Since you don't say anything about the amount of voltage or current you are switching, nobody knows if it will work in your circuit.
  17. audioguru2

    Negative Voltage Rail Sag

    Hi Mr. Freckles, err, Mr. Heckles, ;D I don't know which ICs you can buy. I can get nearly anything. The voltage reference is the opamp's reference that it compares the output voltage to. When the output voltage begins to drop then the opamp increases the input voltage to the ICL7660 so its...
  18. audioguru2

    0-30 Vdc Stabilized Power Supply

    Why would anybody run an audio amp continuously at full power? It isn't a tool, it plays music that has a peak to average ratio of 10:1. A 100W amp averages only 10W when playing music loud, when the peaks clip a little. Maybe you are thinking of abuse to amps by rock groups. They use heavy-duty...
  19. audioguru2

    i need help extending the keys finder project. can someone help me out????

    Hi Logan, You could use a low power LM324 quad opamp instead of the Cmos inverters IC and design the bandpass filter to operate better. The supply current will be about 1mA and an expensive and fairly large CR2430 3V lithium coin cell battery will last only about 12 days if the circuit doesn't...
  20. audioguru2

    i need help extending the keys finder project. can someone help me out????

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