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  1. Alec_t

    High purity Germanium detector design related clarifications

    Measure the density of the (cracked) plate. That will be a guide as to what the material is.
  2. Alec_t

    Controlling Speed of Motor

    Could you use the turntable drive from an old microwave? Or would that be too slow?
  3. Alec_t

    Circuit Element for variable current control

    Welcome to EP! What are the sources? What voltage? What current?
  4. Alec_t

    Bush Dab radio keep turning itself off

    Agreed, it could well be something in the power supply/regulator which cuts off the radio when the voltage drops below a certain level. Are these rechargeable batteries?
  5. Alec_t

    Wahl "Peanut" Electric Razor blown

    Welcome to EP! The most likely fault is a burnt-out coil. I doubt repair would be economical.
  6. Alec_t

    Sound activated switch

    Welcome to EP! Post a link to the 9V switch spec or datasheet and someone here should be able to suggest a way to interface the switch to the valve.
  7. Alec_t

    Need help, 12v water pump - wire a wall adapter ? Bare wires.

    If 3A is the running current then the start-up/stall current will be much higher. A cheap 4A supply may not survive.
  8. Alec_t

    What sensor can be used to my IOT device?

    I don't think there is an unambiguous direct correlation between emotion and heart beat rate or frequency. For example, strenuous exercise increases heart rate, but whereas that might be exhilarating for one person it could cause suffering in another person. The intensity measurement would be...
  9. Alec_t

    Newark / Farnell / Element 14 become my new "supplier of last resort"

    I would have no objection to a vendor doing that, provided they were honest, accurate and up-to-date about what they actually have in stock or when delivery of non-stock items would occur.
  10. Alec_t

    Accuracy of digital multi-meters?

    As Bob says. DMMs commonly have a ~10 Meg impedance. 10 Meg in parallel with 200k brings the resistance down by ~2%.
  11. Alec_t

    Windmill vane controller

    What exactly do you mean by 'vane'? Full-size windmills have so-called 'sails', each of which may consist of several pivotable 'shutters'. The shutters can be mechanically controlled to regulate the mill rotation speed in different wind speeds.
  12. Alec_t

    Information on wiring a 5vdc fan and a 6vdc pump in a circuit

    Oops. Re post #10, scrub the reference to 2A being fine. I overlooked the pump start-up current that Tedstruk mentions above.
  13. Alec_t

    Information on wiring a 5vdc fan and a 6vdc pump in a circuit

    They draw what current they need, so as long as the adapter is rated for at least their total current it's fine. A 2A adapter is good, because it allows a good safety margin. It is never good practice to run things at their absolute maximum rating.
  14. Alec_t

    Low cost (single ended) soldering pins?

    Seems they're called PC pins. Something here suitable?
  15. Alec_t

    Transistor gate voltage

    With a FET, as above, you wouldn't need a resistor in series with the gate, but you would need one (say 33k or so, not critical) between the gate and the source pins to ensure the FET turns off when the switch opens.
  16. Alec_t

    Low cost (single ended) soldering pins?

    Pin cross section is 0.025 x 0.025 inches. Here's the datasheet.
  17. Alec_t

    Low cost (single ended) soldering pins?

    ... or something like this?
  18. Alec_t

    Information on wiring a 5vdc fan and a 6vdc pump in a circuit

    Welcome to EP! Why? Can't you run both the fan and pump from a mains-to-6VDC power supply (wall-wart)? The fan probably wouldn't complain if the supply were 6V, but to be safe you could run it with a silicon diode (a 1N 4003, say) in series. Putting fan and pump in series wouldn't work. The...
  19. Alec_t

    Anyone know what this is?

    Optical fibre?
  20. Alec_t

    need basic schematic for a 12v gradual power up for small water pump

    Methinks the FET would turn on fairly abruptly, so the current would not change smoothly over 3 sec. A few extra components could help to linearise the current ramp, but doing so would increase the heating of the FET.
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