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  1. (*steve*)

    How sweet it is to be an idiot

    It was completely off topic for the place it was posted. It was also clearly a pre-prepared rant. If you want to respond to it I can PM you a copy and maybe @Ian can get you his email address so you can work it through with him... :-D In a similar vein, and less than 24 hours earlier, I did...
  2. (*steve*)

    How sweet it is to be an idiot

    I have just deleted a massive post and banned the author. It basically went into great detail about how moon landings are impossible and that they were faked. Although I didn't read all of it, I think the arguments suggested that all spaceflight was impossible (including unmanned spaceflight)...
  3. (*steve*)

    nixie clock problem

    Was it a retail purchase? Have you contacted whoever you bought it from?
  4. (*steve*)

    I just replaced the capacitors in two Gateway monitors and turned on then died again

    The other side of the board is just as important. Did you use low ESR capacitors? Are the capacitors around the right way? Post images in the thread if possible. See our resource section for hints on taking more useful photos. <-- link
  5. (*steve*)

    Light therapy device

    Yeah, and I've been trying to find time to design the board for you. I've failed so far :-(
  6. (*steve*)

    Need help in designing a simple device

    What is the source of your voltages? If they are very high impedance then I can understand input 1 affecting it's source, but not input 2. The question relates to them actually being outputs. Are they? And I have assumed they are relative to the ground voltage of the op amp. I've assumed...
  7. (*steve*)

    Float Charger

    For NiMH, the easiest method would be either a dedicated chipset or a microcontroller and lots of programming. Detecting SOC for these batteries is non-trivial.
  8. (*steve*)

    Float Charger

    Connect them as shown in the schematic. In series.
  9. (*steve*)

    Float Charger

    There are 4 diodes. The green LED lights if there is input power, or if sufficiently charged batteries are present. The red LED lights when input power is connected, sufficiently charged batteries are connected, but not if the batteries are shorted. The diode D1 protects the circuit from...
  10. (*steve*)

    HP 8594E

    I have one of these at home. But rather than appearing to have all the information you need at my fingertips, try googling for "CAL: RES BW AMP FAIL." Yeah, I know. I'm giving all my secrets away. But even if I try to keep it to myself I'm sure that some day word of this search engine will...
  11. (*steve*)

    Help identifying burned diode

    Firstly, you need to read this. Secondly, fix the solder joint. I agree it looks suspicious. There's no indications of what those diodes are. But there's several of them, so maybe they're all the same. And maybe they're regular diodes? A 1N4148 might be a suitable replacement. Sides...
  12. (*steve*)

    Negative Voltage

    Except for the statement above, yes. It's more like saying that the passengers in the top deck of an A380 are at a higher altitude than those in the lower deck. That is true if the plane is on the ground, 40,000 feet in the air, or parked somewhere below sea level. In your case, the anode...
  13. (*steve*)

    Apple iMac 21.5" A1418 820-3302A Blown Caps

    If the board if charred, it will be very difficult to repair. I would suggest that for a multi layer board repair is not viable.
  14. (*steve*)

    bleeders and what I am doing....

    What are you trying to do? I really can't understand what you're up to.
  15. (*steve*)

    MPPT Solar charge controller

    A reasonable working assumption is that the fault is in the voltage measurement part of the circuit (it may not be, but it offers a way to direct our initial investigation. What you would probably be looking for is a thin track coming off the +ve to the battery which leads to maybe a couple of...
  16. (*steve*)

    Need help in designing a simple device

    Here is the diagram I was referring to: The datasheet is for single, dual, and quad op-amps. You need the quad. It is the lower right one. The semicircle at the top of the diagram is often present on the chip itself. An alternative is a circular depression near pin 1. In some cases ((not...
  17. (*steve*)

    Ball wall target board

    This thread has some interesting information on how to detect the time between 2 inputs changing. They note that a resolution of a couple of millionths of a second is relatively easy, and with some devices a small fraction of a millionth of a second can be achieved. Other microcontrollers may...
  18. (*steve*)

    Ball wall target board

    That circuit will give you the timing of the pulse, but not the magnitude. However it is simple. Piezo transducers have been used with microcontrollers to detect things being struck, so googling "piezo input Arduino" might yield some useful results.
  19. (*steve*)

    Need help in designing a simple device

    You should be looking at the far right set of pin numbers. Pin 4 (Vdd) is the positive supply pin (+5V). Pin 11 (Vss) is the ground pin Each op amp had two inputs, the inverting input (labeled -) and the non-inverting input (labelled +). These are positioned on one side of the triangle...
  20. (*steve*)

    Need help in designing a simple device

    Yes Yes. As does the ground pin of the op amp (not shown), and this ground is also the reference against which the output voltages are measured.
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