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  1. crutschow

    Help identifying old lab equipment

    Apparently-- Is necro better?
  2. crutschow

    Help identifying old lab equipment

    Yup, another narco post.
  3. crutschow

    Can someone suggest me an upgrade for my car that doesn’t require any wire cutting or voids insurance and warranty, but still gives an excellent econo

    What year is your car? Modern cars are pretty well optimized for both performance and fuel economy. If you do anything to improve its power, than you will likely get poorer economy.
  4. crutschow

    2.4v NICAD CHARGER?

    Below is a CC-CV charger using the common LM317 regulator and TLV431 programmable voltage reference: It charges the batteries at 210 mA constant-current and limits the charge voltage to 3V. The TLV431 limits the voltage when the Vref voltage from the R1/R3 divider reaches 1.24V.
  5. crutschow

    Backyard DIY Auto Repair and Backyard DIY Electronics Repair

    One difference to me between electronics and mechanics, is that mechanics would seem more visually "intuitive". For example, you can likely pretty well understand how common vehicle engines work, and what all the parts do when you take them apart, if you understand the basic 4-stroke Otto or...
  6. crutschow

    LiFePo4 100 AH battery charger

    Reminds me of someone else who posts on this forum. :rolleyes:
  7. crutschow

    LiFePo4 100 AH battery charger

    That's per cell of course. A 12V LiFePo4 battery has 4 cells.
  8. crutschow

    Replace power MOSFET in subwoofer plate amp, Sledge STA-1000D

    And where did you? MOSFET "saturation" is in the active or linear region, not fully on, which is in the ohmic region. For some odd reason this is different than a BJT where the saturation region is, of course, fully on.
  9. crutschow

    Combining two +12v car outputs

    What is the high and low beam current of the lamps?
  10. crutschow

    Combining two +12v car outputs

    The simplest way is to use a diode between the two wires (diode anode to high-beam wire). That will power the low-beam when the high-beam is on. The diode needs to be rated for the low beam current, and Schottky type diodes have the lowest voltage drop when conducting.
  11. crutschow

    Minimize Ripple in Rectifier by Waveform, Polarity, Bridge-Type, Inductor, Trafo?

    There a "swinging chokes" made for power supplies that have a high inductance an low currents, so the inductor doesn't "drop out" between half-cycles, which otherwise would increase the output ripple volage at those low currents.
  12. crutschow

    RCA Console Protection/DC Centering Mod

    100mV into an 8 ohm speaker generates only about 13mA of current, so that should not be a problem.
  13. crutschow

    Transformer overvoltage

    Here's a tracking preregulator using a high-voltage MOSFET and Zener, that will tolerate an output short.
  14. crutschow

    Transformer overvoltage

    One thing to be aware of is that the tracking regulator has near the full voltage across it in the event of an output short to ground.
  15. crutschow

    Electronics Knowledge and Skill Level of This Forum

    Yes. Electronic consumer repair is now mostly limited to factory warranty service, and that usually consists of replacing whole modules or circuit boards in the device, so not a lot of electronic knowledge is really needed for that.
  16. crutschow

    Electronics Knowledge and Skill Level of This Forum

    True, those kits are mainly just to assemble a useful device. Those kits I referenced are for learning, not making a permanent product. Look for advanced kits for adults or engineering students. But you remark about a "Throw away" society is a caution, since there is not a lot of electronic...
  17. crutschow

    Electronics Knowledge and Skill Level of This Forum

    John, if you want to start experimenting with electronics to learn, then you might start with one of the many electronic kits available for just that purpose.
  18. crutschow

    A Speaker OHM question

    There should be no problem in using 8 ohm speakers with the amp set to 6 ohms. The only difference may be a slightly lower maximum power into the 8 ohm speakers, but that's shouldn't an issue at normal listening levels.
  19. crutschow

    Alternating L/R 4-way flashers

    SPST has one contact the is normally open. (Normally is relay unenergized). SPDT has two contacts going to one wiper with one contact normally open and one normally closed.
  20. crutschow

    Alternating L/R 4-way flashers

    But the TS has been AWOL since Saturday, so perhaps this is all moot.
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