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  1. Minder

    Homemade DC generator(dynamo) with a spinning coil

    A typical hand-mixer has a universal motor, and would make a lousy generator, you would need to rewire the fields in parallel with the armature instead of series to get any output. M.
  2. Minder

    Problems with a Lamp Project and Dimmer Module/Switch.

    This is a typical circuit for a dimmer, some components can vary but virtually the same principle, the on/off switch would go in the Live cond lead. If your load was less than 3amps then I don't really see where you went wrong, maybe have to open it and see if any components are blown? M.
  3. Minder

    tube (valve) help

    Would appear the audio section is not working so start in the audio output section, a meter lead or touch a probe to the grid should produce a hum or click, especially if you place your finger on the probe. Ensure the anode/power +v is present. M.
  4. Minder

    Simple power supply?

    If this is a Nichrome foam cutter etc, the Triac is the simplest way to go IMO. M..
  5. Minder

    Simple power supply?

    Basically you are using the wrong type pf control, it not very efficient even if it works. Many use a light dimmer on the primary side of the transformer, I prefer to use one on the secondary, for that you have to use a home built one intended for the lower voltage using a Triac and a couple of...
  6. Minder

    Old AC DC power supply with mechanical rectifier ?

    The way the synchronous rectifier works is where the primary of a step up transformer is fed from a DC supply and the primary is switched in polarity very rapidly by a set of contacts, the secondary is also switched in synchronism with the primary and the resultant secondary DC voltage is used...
  7. Minder

    Old AC DC power supply with mechanical rectifier ?

    The only mechanical rectifier I am aware of is the synchronous vibrator used in vintage car radio etc. This does not appear to be a version of this however, but a proper drawn schematic may show more info. Obviously appears to be some home built device. M.
  8. Minder

    Test Rig

    Is this for an academic exercise as the off the shelf ones are fairly sophisticated and Cheap! May not be worth the exercise to make. M.
  9. Minder

    Heating elements for own built terranium

    You probably need to get the hand tool version of variable control rather than the lighter lamp style, also needs to be 240v rated if using them in series. M.
  10. Minder

    Test Rig

    Is there any significant current drawn from the various junctions? Li-Po cell is around 3.3 - 3.6, one way would be to string a number of rectifiers in series to provide a constant volt drop at the junctions, it may require some individual selection of diodes etc. And also depend on what you are...
  11. Minder

    Beginner ... ferrite core coil for crystal set

    As a kid we did not have access to Ferrite whatsoever, we just used a coil, we also used the first solid state device used in electronics, a lump of Galena! (cats whisker). M.
  12. Minder

    Not enough current to trigger relay.

    Only disappears for me when I log off and read the posts?o_O M.
  13. Minder

    Float Switch for 240V pump using a relay

    Yes probably, There are also many that state the contact voltage insulation rating. You may find a salvaged one from a typical auto may be better than from China, although many do profess the high voltage on the side. M.
  14. Minder

    Float Switch for 240V pump using a relay

    Do you have an auto wrecker near you? the 12vdc coil relays are plentiful and the vast majority have 500vac insulation/dielectric rating between the coil and the contact. M.
  15. Minder

    Homemade DC generator(dynamo) with a spinning coil

    For which you would need DC somehow!;) M.
  16. Minder

    Not enough current to trigger relay.

    Canadian flag shown? M.
  17. Minder

    Homemade DC generator(dynamo) with a spinning coil

    You may have seen bicycle light generators that run against the wheel being refered to them as 'Dynamo's', but being AC, strictly speaking they are alternators., M.
  18. Minder

    Homemade DC generator(dynamo) with a spinning coil

    Yes a dynamo has usually been associated with a DC generator, what you described was an AC version (alternator). Similar to what you get when back-feeding a common BLDC motor etc. Edisons original used a wound field and relied on the existence of residual magnetism, and then pulled itself up by...
  19. Minder

    Need help on servo motor output gear sizing

    I realize when I re read the OP. Here is a couple of links that may help. 25 SEGMENTS/ Ø5.96(FUTABA TYPE) https://sites.google.com/site/3dprinterlist/home/tutorials/more-on-rc-servo-s M.
  20. Minder

    Beginner ... ferrite core coil for crystal set

    Using modern magnet wire the insulation is good enough to wind directly on top if needed. Also unless you are aiming for a particular RF spectrum, the amount of LW-MW signals out there are plentiful compared to 80 years ago when the cats whisker radio was becoming popular. I would also suggest...
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