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  1. (*steve*)

    Micronta VOM

    You're best off paralleling other resistors rather than using a trimmer. In the short term it might work, but the full 500mA is going through this, so a lot will be demanded from the trimmer.
  2. (*steve*)

    Transistor Analysis

    Vce(sat) is given an 0.15V when Ic is 10mA. 0.5mA of base current (Ib) is required. The hfe is only listed as a minimum value (30). The rest of the datasheet might give more information, but clearly for saturation ib > Ic / hfe.
  3. (*steve*)

    The curve of the sun?

    There is no simple formula, but the calculations are not magic. The hardest part is determining the local time at a location because this is affected by politics as well as mathematics. Cannulating GMT time is easier. Many web sites used for projecting solar panel performance can do these...
  4. (*steve*)

    I need a voltage follower with >= 1Amp output for experiments

    It looks to me like the LTC3300 is exactly what you need. It can transfer (via a transformer isolated power supply) charge from stronger cells to weaker cells (during discharge) and from weaker cells to stronger cells (during charge). This is exactly what I mentioned in post #17. A single...
  5. (*steve*)

    I need a voltage follower with >= 1Amp output for experiments

    Firstly, I have no idea why the current average cell voltage is particularly meaningful. Secondly, if this voltage is being generated from the battery pack itself, you have a significant isolation problem, not to mention one with physics. For this to have a chance of working, you must use a...
  6. (*steve*)

    Transistor Analysis

    I think you meant Vbe > Vce. You may need to have 3 to 10 times that base current for saturation. The datasheet may have enough information specified for its quoted Vce(sat) to allow you to compare the ib in this case with what you would calculate above. It's also worth noting that hfe...
  7. (*steve*)

    Using Electronics to Measure Electric Potential around a High-Voltage Insulator

    As I see it, any resistive divider is going to load down the input. Added to that, it will provide a conductive path that might cause the insulator to flash over. Detecting the gradient of the electric field might be easier. Google "electric field mill" for some information
  8. (*steve*)

    Microcontroller

    Do you have the potentiometer connected as a variable voltage divider from the microcontroller power supply? Do you realise that the microcontroller drives the display, the display doesn't "read" the microcontroller. Have you ever programmed this type of microcontroller (or any...
  9. (*steve*)

    Transistor Analysis

    Why are you concerned that the voltage at the emitter is zero volts? Do you understand that the voltage at the negative end of the battery would also be labeled as 0V, and the emitter is at this potential because it is connected to it? The voltage at the collector is the voltage at the emitter...
  10. (*steve*)

    High Frequency rated cables

    Three are three ways power can be lost from coax: Resistive Dielectric losses Radiation losses Resistive losses are simply due to the electrical resistance of the conductors. Because of skin effects, the total mass of the conductor is less important than its surface area. The centre...
  11. (*steve*)

    I need a voltage follower with >= 1Amp output for experiments

    Have we changed topics? I've seen only one balancing circuit that's not dissipative (it was for capacitors btw). It used inductors to pump energy from one capacitor to it's neighbor in order to level the voltage in adjacent capacitors. For a BMS, unless you can transfer charge from one cell...
  12. (*steve*)

    Pipe Locator

    Can you post a picture of the board? Even if we can't find anything to ID the transistors, we may be able to suggest some generic replacements to try. Why do you think these transistors are at fault?
  13. (*steve*)

    How does this cable connect exactly?

    I find your ideas intriguing and would like to subscribe to your newsletter.
  14. (*steve*)

    I need a voltage follower with >= 1Amp output for experiments

    I guess you need to consider if a new and more complex circuit is going to deliver benefits. In this case, I'm not sure what problems you'd be solving, but the added complexity and uncertainty is fairly clear.
  15. (*steve*)

    Can anybody explain about how bjt works??

    The appropriate answer is the one which satisfies @shantanu singh's question. He may have meant: How does a bjt work internally? The answer involves a discussion of doping and charge flow. How does a bjt work electrically? Here is where the discussion of it as a three terminal device goes. How...
  16. (*steve*)

    I need a voltage follower with >= 1Amp output for experiments

    This is a problem because as only one transistor is ever on, the would not be a path for current to flow. In addition to that it would be problematic as to where to connect the feedback loop. The reason I asked if you knew how transistors worked is that it is kinda traditional to understand...
  17. (*steve*)

    Led Flashlight Help

    Yeah, by "normal" I mean an airline cell or similar (even that leaky carbon-zinc one) as opposed to something with a very low internal impedance. Most rechargeable cells have significant lower internal resistance.
  18. (*steve*)

    Finding a good soldering iron....

    I still use good old kester 44 (well, that's my latest "good" solder.). It's the 0.8mm solder with the 3% flux content. As mentioned the flux is a pig to remove, but I think it's also one of the safest to be allowed to remain. Back to them fluxes,. I was taught that HCl + Zn was "killed...
  19. (*steve*)

    Identifying blown transistors

    Oh ok, so this it from a flash FOR a DSLR, not the flash IN a DSLR. That may mean there's less damage (I.E. the thing that failed is cheaper. Did your DSLR survive unscathed? The hot shoe can be pretty intolerant of high voltages. Is it a name brand flash, or a cheap noname thing?
  20. (*steve*)

    74HC oscillator, how fast?

    Yeah, but that oscillator was producing a very weird signal. Look at the one preceding it. That's 1.66V p-p. They're not practical oscillators, but they're fun.
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