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  1. duke37

    Shaded Pole Fan Motor - Speed Control Question

    Try a series resistance, experimentation will be needed.
  2. duke37

    A zener diode question

    All seems to be correct, congratulations.
  3. duke37

    A zener diode question

    The diagram shows Vo=Vz but does not show where the output would be connected. The meter is to measure the current through the bypass as the resistor is changed.
  4. duke37

    A zener diode question

    56mA is the current through the 100Ω resistor. This goes two ways, some through the zener and some through the series resistors (2.3mA) so what is left to go through the zener?
  5. duke37

    A zener diode question

    Put some brackets in your equations to define what should be calculated first. Thus 10-5.6/100 should read (10-5.6)/100 44mA is NOT Iz 5.6/(220+2k2)=2.3mA correct
  6. duke37

    Brig 001 amp: Left audio channel allways strangely quits working after some minutes

    It is apparent that you have a stereo amplifier so you can compare one amplifier with the other. If both speakers can have output in some conditions, then both amplifiers are working and the problem is the input. I would agree with a switch or volume control problem.
  7. duke37

    Must convert LED strip to 12 volt

    And make sure that the polarity is correct.
  8. duke37

    How to connect a windshield wiper motor to a battery

    A wiper motor could have three carbon brushes. The wires to the two brushes which are opposite each other should be used for the supply. If there is a third brush, this should be used together with the other brush which is furthest away. If you use the two adjacent brushes, then you will get low...
  9. duke37

    Must convert LED strip to 12 volt

    It looks as if the PSU is 12V DC and a 12V battery would replace this without any other modification.
  10. duke37

    Power supply can't get zero volts

    A Zener diode between the 741 and 3055 will solve the op-amp output problem but I have not studied the input requirements of the 741.
  11. duke37

    Salty ground voltage

    If you cover the electrode with an insulating film, then it will not be an electrode.
  12. duke37

    Salty ground voltage

    If the copper has diffused away from the electrode it will not be possible to recover it. Copper can be refined by electrolysis. Aluminium cannot be plated, it is much too reactive and will be locked in a compund. Aluminium is produced by electrolysis of molten aluminium fluoride to produce...
  13. duke37

    Build my own step up transformer 1800s style to power tesla coil ?

    15kV at 300MA is 4.5GW ? You need a fair sized power station. :)
  14. duke37

    Build my own step up transformer 1800s style to power tesla coil ?

    For transformer design, search "Ludens transformer".
  15. duke37

    The collapse of a magnetic field

    This is the circuit of a boost convertor for increasing the input voltage to what is required. They are used in many situations and there is much information on the net. Normally a diode is placed across switch2 so that the current can pass instantly. If the voltage drop of the diode is too...
  16. duke37

    Scope

    The capacitance will affect high frequency measurements. Recently I was looking at some intermediate frequency transformers running at a modest 455kHz. They had 100pF capacitors in them. Adding 13pF would drop the resonant frequency significantly. 50Ω is the most common impedance used in high...
  17. duke37

    Inverter Modifications

    Why do you think that you can make a more efficient power convertor than a commercial one?
  18. duke37

    3-phase ac wind generator problems

    I see no problem with leaving it unconnected. Perhaps this goes to the diversion load which is then switched to ground by the controller. This is all suposition.
  19. duke37

    3-phase ac wind generator problems

    It looks as if you have a 3 phase rectifier with an extra 3 output diodes to produce two independant supplies thus the battery will not feed the diversion load.
  20. duke37

    Inverter Modifications

    Look up the data sheet. Ct = 100nF, Rt = 280k should be about right. If you have a UPS, why not use that?
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