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  1. (*steve*)

    5 decade old battery pack bridge

    In response to your last two posts: "No" The 1N881 is just a normal rectifier diode. Those really bad chargers just use a resistor to see the current.
  2. (*steve*)

    Si826x gate driver keeps failing

    It sounds like you've done a lot of sensible things to troubleshoot the problem. Have you programmed dead time between turning one mosfet off and the other on? If you haven't, it is possible to have a brief high current pulse going through both MOSFETs. This typically causes some heating...
  3. (*steve*)

    ISO a particular switch. Don't know what it's called/to look for

    Another thing is that cats can be very wary of surfaces that are not firm. If operation of the switch moves the platform too much, the cat might not want to step on it. A switch is easy, and it's great if it works, but there are many other ways to skin a cat... ummmm, perhaps not the best...
  4. (*steve*)

    Si826x gate driver keeps failing

    My first thought was that the SMAJ28CA-E3/61 was conducting and loading down the rail (which is just a 10μF cap), but this is a 28V device. Incidentally, it is rated to allow 28V across it. It clips at 31V or more. This is higher than the Vgs(max) (30V) and also significantly higher than the...
  5. (*steve*)

    5 decade old battery pack bridge

    OK, now I'm using something with a larger screen I can see they're 6V batteries. I suspect they're a stack of nicad cells - does it look like 5 small cells? Similar answer, find modern batteries which fit (maybe lithium?) and use an external charger.
  6. (*steve*)

    Si826x gate driver keeps failing

    What is the failure mode? Is it U1 or U3 that are failing (or both)?
  7. (*steve*)

    5 decade old battery pack bridge

    My guess is that the batteries had gone short circuit after being left discharged so long. Attempting to charge them destroyed the resistor. I would convert the device to use normal AA batteries, then get some AA nicads and a decent charger. The built in charger is bad news.
  8. (*steve*)

    Voltage Regulation Using Diodes Problem

    Please go to the list of forums and then select the Homework forum. Click on the first post. or just go here. I understand that you may be looking at posts that are new rather than going in via the list of forums and browsing the posts. As such you may not be aware of the rules of the...
  9. (*steve*)

    Ic=C x dv/dt

    I assume you're talking to me. At this point we're not talking to anyone doing homework.
  10. (*steve*)

    Ic=C x dv/dt

    Yeah, and although we all understand what you meant, "a voltage applied to a wire", if applied equally to the whole wire (i.e. there is no gradient) won't result in a net force on electrons in one direction or the other. And of course electrons aren't current. The speed of those electrons...
  11. (*steve*)

    Ic=C x dv/dt

    More precisely, to the electric field within the wire. (I hate loose and imprecise statements ;-))
  12. (*steve*)

    EPROM and UV-erasing light general questions

    Each time you program them you are forcing electrons through an insulating layer. That will cause cumulative damage. However, if you only program them once every 20 years, they will last far longer than you will. The best indication would be to look up the datasheet for the device. It may...
  13. (*steve*)

    EPROM and UV-erasing light general questions

    Just be careful with the UV. A little bit of leakage won't be a huge issue, but don't put your face against the tube. Depending on the wavelength, you can get cataracts, or just really bad sunburn. EPROMs store a bit by burying a charge in a "floating gate". Over time this charge can leak...
  14. (*steve*)

    Attiny85 and unrecognized HIGH levels

    Here is the circuit I recommend: R1 limits the current through the diodes R2 limits the current through the microcontroller's input protection (which is often similar to the two diodes shown here) If you use Schottky diodes for D1 and D2, R2 may not be required. Be careful that the maximum...
  15. (*steve*)

    Creating a 16-1 multiplexer from four 4-1 multiplexers and one 4-2 decoder

    Did you read the bit about us not giving the answers?
  16. (*steve*)

    Attiny85 and unrecognized HIGH levels

    Using a zener on its own may cause heavy currents to flow. You'll want to add some series resistance to limit the current. 3.3V sends have very soft knees. I'd recommend a pair of diodes and a pair of resistors. I can't draw the schematic right now. I'll try to do it in about 12 hours of...
  17. (*steve*)

    Attiny85 and unrecognized HIGH levels

    I guess you're wanting to express exasperation. You've succeeded. However, if you want anything more than vague ideas, you'll need to provide more than vague details. My guesses are noise, ground bounce, ringing, stay capacitance or a low level signal.
  18. (*steve*)

    Embedded Project In Linux

    Type "man sdcc" You will get the manual page for sdcc. If you still have problems I would advise you to find a support group for sdcc.
  19. (*steve*)

    Working of a JK Flip-Flop. Help needed with the circuit.

    All of those are possibilities. My suggestion gives you full control over when the signal transition occurs. This is great for learning what happens. An oscillator (e.g. a 555) is fine when you want something to run with a continuous clock. But this will generally be too fast for you to set...
  20. (*steve*)

    Proper Ground

    The car chassis has less resistance than a very long wire.
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