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  1. kellys_eye

    Isolating two outputs from an input

    You will never get 'isolation' while you have a common ground return.
  2. kellys_eye

    Wireless wind vane alert

    What distance from farm to home? Is it a distance that could be covered by a simpler radio signal? There are radio-data modules that have ranges up to 50km and very low price point, low operating current and very easily adapted to your needs. Look up LoRa modules. With a wind sensor and...
  3. kellys_eye

    Determining LED values

    Unless I'm looking to match LED brilliance I tend not to bother calculating values of resistance for LEDs but instead opt for 1kΩ every time, every colour and for every voltage from 5V up to 24V. At 5V this means passing 3mA (ish) in a red LED and 2mA in a white LED (and all others, some...
  4. kellys_eye

    Stopwatch circuit with milliseconds

    The decimal point can be simply hard-wired 'on' as required. Find a circuit that uses (say) a 1MHz crystal and the 4017 decade divider (or the 7490 - old-school stuff) but instead of dividing the signal down to 1 second intervals simply tap the clock off at the 1mS interval (1kHz point). 1MHz...
  5. kellys_eye

    Wireless wind vane alert

    Detecting the wind speed is easy - as is creating a signal to 'switch' something. The hardest part (for someone with limited access to tech parts) is sending the signal via GSM or internet. It would be easier to fit a clock (timer) and solenoid-activated valve such that the valve is opened if...
  6. kellys_eye

    Determining LED values

    You can do it 'rule of thumb' using just the colour, from around 1.2V for red to 3.6V for white. But I tend to break them down into the Red/Yellows (using 2V as a figure), the Green/Blues (2.5V) and Violet/White (3.5V) and series resistor calculations will be near enough for most purposes.
  7. kellys_eye

    Wiring mental block

    Most likely serially-addressed LEDs and programmed via micro controller. Unless you can access the software you have no chance of achieving your aim.
  8. kellys_eye

    Resistors, Capacitors, Zener diodes... Why the funny values?

    Much of the impression you get of 'mass knowledge' is the result of 'application' of the basic theory that is learned then understood. All electronics can be boiled down to basic circuit theory so your impression that we have intimate knowledge of 'everything' is actually our ability to derive...
  9. kellys_eye

    Getting ready to manufacture something and need advice for detachable battery pack.

    Waterproof? Or splash proof? There's a world of difference and a leap in cost between them. You can draw around 500mA from a micro USB socket.
  10. kellys_eye

    Single phase

    10hp usually defines the motive unit used to generate the energy. The engine driving the generator. If you try to draw more power than the motive unit can deliver you will slow and/or stall the that motive unit. As stated, 10hp equates to 7.5kW (or thereabouts) so drawing 8kW may cause the...
  11. kellys_eye

    Vizio E470i-AO television has a black screen. Which part do I replace?

    When LED TV back lights fail it is usually because one of the LEDs in the strips on the rear of the LCD panel has gone short. They are an easy fix but........ First you have to find a replacement LED strip - replacing the individual LEDs isn't easy. The strips are available as 'left or right'...
  12. kellys_eye

    Yamaha rx-v596rds

    Manual: https://www.manualslib.com/manual/340482/Yamaha-Rx-V596rds.html You HAVE checked for all possible 'user errors' haven't you? Otherwise its potentially a power supply fault. Could be anything really..... You will need to dismantle the unit and post clear pictures of the power supply...
  13. kellys_eye

    Stopwatch circuit with milliseconds

    Any timer displaying 'seconds' could be readily adapted to mS simply by changing the programmed divisor that produces the 'count' pulse. In the case of a discrete construction this would mean (for example) leaving out the last divider in the timing chain and getting 1/10th second (or leave two...
  14. kellys_eye

    Motor for back and forth

    ...expanding... the motor power consumption depends on the load place upon it. Heavy 'hands' and/or wind resistance working against the 'hands' will increase the demand on any battery. Measure the 'off load' current (nothing fixed to the drive shaft) and you can work out how long a specific...
  15. kellys_eye

    Piezo Control voltage source

    Their sensitivity is fixed by their physical construction so amplification of anything they produce will be required to make them 'more sensitive'.
  16. kellys_eye

    Acer X223W LCD Monitor

    Why? If you have a problem with it the faults are usually quite common and repairable without recourse to full schematics. Tell us more....
  17. kellys_eye

    What Part is This?

    Well spotted Edd. Must go to Specsavers......
  18. kellys_eye

    I need a detailed Analysis on this circuit

    Sounds like someone wants us to write a working paper on some form of college/uni homework! I've never seen a request so un-subtley put!
  19. kellys_eye

    Getting ready to manufacture something and need advice for detachable battery pack.

    If the device has a recharge socket, why would you want to make the battery 'easily' removable? For 90%+ of its life the battery won't even need to come out - surely? In which case, for the very odd occasion it DID need to be removed, a simple wired plug/socket arrangement would suffice and be...
  20. kellys_eye

    Stepping up the voltage for a Geiger Counter

    The board you linked to in your first post is the best way to go.
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