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  1. (*steve*)

    Hello... Again...

    Tweet. Whistle whistle. Chirp!
  2. (*steve*)

    Wire wound resistors

    There are ways of creating windings which are non inductive. When I say "non inductive" I mean minimally or less inductive because even a straight piece of wire has inductance.
  3. (*steve*)

    High Side switching N mosfet

    As a person with equipment capable of measuring that leakage, I'd have to say you're wrong on that point. However, that's probably not the main source of leakage. There's also leakage across the board, which may be affected by residual flux, humidity, and the type of the board. If your off...
  4. (*steve*)

    Trying to find a step down power module

    No, you can supply a motor with pulses and it will have greater torque at lower speed than if you limit the volage. This means it will start more reliably at slower speeds and be less likely to stall. Having said that, I've found that many 12V PC fans tend to start and run at 5V, and I'm using...
  5. (*steve*)

    Trying to find a step down power module

    For controlling motor speed, a pwm controller will do the job far better. But sure, on those cheap buck regulators you can replace the trimpots with regular potentiometers. The most important thing is to wire them up correctly.
  6. (*steve*)

    Additional rectification necessary for Tom Tom unit?

    Rectification and filtering are two different things. And regulation is a third.
  7. (*steve*)

    Capacitor neutralization circuit not discharging

    Maybe the capacitor has already self discharged? Or maybe you have poor connections. I would connect a multimeter across the capacitor so I had a good indication of the voltage across it. In addition, you are not limiting the current through the LEDs. If you've been discharging into a short...
  8. (*steve*)

    Robot Homing using RF

    Not on its own. That device can't figure out the distance and/or direction to some other location
  9. (*steve*)

    Capacitor neutralization circuit not discharging

    Maybe whatever resistor you have there is to high a value to be able to see any visible light from the led.
  10. (*steve*)

    Resistor value

    Their job is to give people a lot of information, not simple "acceptable" use cases. However, with a small amount of knowledge you can extract enough information to use the device as long as you don't need to get close to the edge cases. I recommend looking at maximum continuous values and not...
  11. (*steve*)

    Resistor value

    That's what I was giving him.
  12. (*steve*)

    Resistor value

    The datasheet says that this device is rated for a continuous load current of 100mA, but allowed a peak of 350mA for 10ms. For a load current of 100mA, the required input current is 0.4 to 1 mA. On the next line they give the typical forward voltage of the input at 5 mA. Based on all of that...
  13. (*steve*)

    WheatStone bridge

    So you understand that there are 4 current paths from C to A, and that at any time only 2 or 3 of them are active?
  14. (*steve*)

    Replacement Ribbon Cable suggestions (HP 97 Calculator)

    Please let us know how it turns out and possibly cross post to hpmuseum.org too. There may be others who have (or will have) this problem, so knowing how viable this is will assist them.
  15. (*steve*)

    I have an RCA LED55C55R120Q 55" LED LCD tv. The screen went black. See details.

    It also may be a power supply failure. I would be checking to see if any of the filter capacitors have unexpectedly high ESR. Without an ESR meter to check them, I'd just replace the filter capacitors.
  16. (*steve*)

    Replacement Ribbon Cable suggestions (HP 97 Calculator)

    Hard wiring it would be my last resort. You'll be working with old, delicate, and irreplaceable boards which are populated with devices that may not have the best static protection. If the items I suggested ship to the US (you're in the US, right), then just order them off the foreign eBay...
  17. (*steve*)

    Bluetooth Doorbell

    Turn down the music. You'll damage your hearing.
  18. (*steve*)

    Replacement Ribbon Cable suggestions (HP 97 Calculator)

    I suppose I should join up to the new forum. You may find posts from me in the old forums :-) Another important thing to know is if the connections are on the same side of the flat flex or the opposite sides. I'm not going to open up my HP97 to find out :-) I'd check out this if you need a...
  19. (*steve*)

    Hello, new member here

    Hi Frank. I'm Steve, and amongst other things I'm a collector of vintage HP calculators.
  20. (*steve*)

    Replacement Ribbon Cable suggestions (HP 97 Calculator)

    Have you tried hpmuseum org? If both ends are plugged in like this, it should be possible to purchase a flat flex to replace this one. What is vital right now is that you get good measurements of the existing interconnector. Width, length of interconnector, length of exposed pads, width of...
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