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  1. HANKMARS

    NiMH battery pack mystery

    I can take a 6 cell battery of fully charged cells and draw 10-11 amps. I can take another 6 cell battery of fully charged cells and draw 10-11 amps. Take any 8 of those cells, put them in my 8 x AA holder and I draw 5-6 amps max. ( 1Ω load ) Various 6 cell holders, various 8 cell holders. It...
  2. HANKMARS

    NiMH battery pack mystery

    The problem may still be the material or connections in the battery holders themselves. If I had 8 dummy batteries, I would be able to most likely observe a discrepancy in conductivity between holders, 6 cell and 8 cell, with my course meter reading. 200Ωs is the finest scale I have right now...
  3. HANKMARS

    NiMH battery pack mystery

    If temp is finely regulated, I say Yes. In this particular case, I can connect 1 Ω load across 6 cell batt, read V across resistor at 10.xxV. Remove 6 cell batt, connect 8 cell batt read 5.xxV, switch 6 cell back in and read 10.xxV. Just that quick. If resistive element internal heats to a temp...
  4. HANKMARS

    NiMH battery pack mystery

    I read your instruction to mean for me to measure voltage across 1ohm WHILE simultaneously measuring current flow, with a meter, I presumed.
  5. HANKMARS

    NiMH battery pack mystery

    My 1 ohm resistor is rated at 100W. Aluminum body, Size of a baby carrot stick. Little bigger. Circuit diagram messy yes trying to convey idea that along with internal resistance, there may be a sort of barrier that has a bias voltage required to allow it to conduct. Let's say that a 1,5 voltage...
  6. HANKMARS

    NiMH battery pack mystery

    Oops. Misunderstood your instructions. I predict a significant drop in current due to my meter in series with circuit.
  7. HANKMARS

    NiMH battery pack mystery

    I do that and consider my voltage reading, across a 1 ohm resistor, to be the value of my current flow, per ohm's law.
  8. HANKMARS

    NiMH battery pack mystery

  9. HANKMARS

    NiMH battery pack mystery

    As the voltage increases across a fixed resistance, current will increase also. Using a 1 ohm resister, the voltage across the resister reads the same as the current value. 6 cells, 1 ohm load reads 10 amps. 8 cells, 1 ohm load reads 5 amps. What happened?
  10. HANKMARS

    NiMH battery pack mystery

    With this theory it seems that you could almost connect enuf cells in series to eventually have no current out. I did series connect 12 cells resulting in a current flow of 9+ amps across a 2 ohm resistance. Test lead resistance explains some loss in current. I recognize internal resistance in a...
  11. HANKMARS

    NiMH battery pack mystery

    When connecting cells in parallel, the V out will be at or nearly at the voltage of the lowest voltage cell. I currently do not believe that cells in series will drop their current flow to the lowest "charged" cell. If a cell is faulty because of a manufacturing error or because of damage, then...
  12. HANKMARS

    NiMH battery pack mystery

    I most likely will make a stop at battery university. The current output curve of NiMH cells is nearly flat in relation to V out.
  13. HANKMARS

    draw a constant current from a lead acid battery

    Good point
  14. HANKMARS

    draw a constant current from a lead acid battery

    If this is an assignment then this may not help but I have found off-the-shelf constant current sources mostly reliable and quite time saving. Also I often use the net with a call similar to, "Images constant current source. " Many images are inaccurate and not much more than a block diagram but...
  15. HANKMARS

    NiMH battery pack mystery

    I use 6 - AA NiMH cells together in a 6 x AA battery holder. My application typically uses a timed on state drawing 50mA to 2A. In this application, I have sufficient power to drive the device for 90 to 120 minutes. These times should improve as I refine my circuit values. Each cell has a rating...
  16. HANKMARS

    Transistor prototype photo

    Back in the day, I had a Sansui (sic?) tube type audio amplifier. It had a transformer about the size of a small toaster. I will contend that that amp had a much "richer" sound than the solid state amps of the time. It has been mentioned to me, and I am inclined to agree, that the timber of the...
  17. HANKMARS

    Transistor prototype photo

    Thru out the world those that despise the worship of money generally phase it, " Worshiping the Almighty Dollar. " Not the Almighty Pound or franc or yen or peso.
  18. HANKMARS

    Transistor prototype photo

    Clearly a matter of definition of terms.
  19. HANKMARS

    Transistor prototype photo

    Interesting site. Thanks. The accompanying photo file concerns Iowa State University, located in Ames, Iowa. I was born and raised 8 miles from Ames so I like to occasionally shill for them. I did not attend ISU but did many visits. When I studied electronics, I did some written or maybe oral...
  20. HANKMARS

    FET question

    I think the Wiki article mentioned that since the conducting channel of a PMOS device is doped with a P type substance, holes, as opposed to electrons, will be the majority current carrier. The explanation was that holes do not have the mobility of electrons. I honestly do not know if this is an...
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