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  1. kellys_eye

    Starter Project: Camera and Live Feed

    Three statements that really don't mix! That's a bit like "I know how to use a knife and fork but I really want to do open heart surgery". You need to know more about the basics of what you're wanting to achieve - first principles if you will and, certainly, the knowledge of the protocols...
  2. kellys_eye

    Why are there not millions of usable frequencies?

    Getting a filter of 'zero bandwidth' would be impossible therefore you could never separate the signals for reception. Bit pointless having 'infinite' transmit channels if you can't separate them at the receiver....... Given that the RF spectrum is many 100's of GHz wide you could transmit...
  3. kellys_eye

    FM transmitter for MP3

    Your understanding of the adapter is basically correct. The only thing missing is that it will have an internal change-over switch (either electronic or a simple relay) that feeds the antenna signal to the radio or cuts it off when you use it for MP3s The standard MP3-FM transmitters will work...
  4. kellys_eye

    Kodak Carousel Projector

    |Time to 'get modern' and have the slides professionally scanned for display on TV/PC/Tablet (and forwarding to friends/relatives etc)
  5. kellys_eye

    How to make my thermocol incubator marketable?

    1. Channel the polysytrene box to run the wires 'sub surface'. 2. Get someone to design/print a card 'sleeve' to wrap around the box, covering the hidden wires and making the thing a lot more attractive. 3. Get rid of the chunky mains connection boxes on the side - consider using a separate PSU...
  6. kellys_eye

    How to make my thermocol incubator marketable?

    Check out the opposition first. You may find that the market for such devices is already saturated or, at the very least, difficult to make a profit in. Unless you have some special method to reduce production costs that no-one else is exploiting you may find taking the product to market COSTS...
  7. kellys_eye

    nordictrack 2420

    So was the OP... :p
  8. kellys_eye

    nordictrack 2420

    It's faulty.
  9. kellys_eye

    Kole Audio TRAX1-5500D Missing Component?

    One pad (opposite the three) is a soldered 'tab' - usually connected to one of the other three pins - but it could be a simple LM317 (or its equivalent) based on the resistors adjacent to the other pads. Can we see a close up WITHOUT the red marking?
  10. kellys_eye

    Rutland ESB57 Energiser low voltage help!

    Change the big capacitor! It's a common cause for 'low' output. Just be sure to get a decent quality replacement.
  11. kellys_eye

    Crystal sets - How do they work? :) (with real diodes)

    If you want to do energy harvesting then purchase a house that sits under HV transmission lines....... As per post #2, the levels of energy are not of usable quantities.
  12. kellys_eye

    Questions about chargers & charging a 2kWh section of a Chevrolet Volt battery

    The basic principle behind a BMS is fairly simple - there is no good reason why they should be expensive other than an ability to 'gouge the market whilst the going is good'. People have built their own BMS boards for a for less than $500 but the abundance of cheap Chinese supplies (for now!)...
  13. kellys_eye

    volume/frequency activated gates/triggers

    Amplitude is 'easy' - any circuit used to indicate signal level (LM3915/LED bar) can be 'tapped' to take off a switching signal. Frequency is less easy - you have to consider the frequency and the bandwidth but it's still (fairly) easy to achieve and, 'back in the day', the NE567 was commonly used.
  14. kellys_eye

    Electric Motor Conversion European - USA

    Get hold of a UK site transformer - the big yellow 'bricks' used to use 110V power tools on a 240V supply. Used in reverse - perfectly acceptable - it will provide up to 3kW of power and no issues.
  15. kellys_eye

    Basic understanding of low pass filter

    Read posts #2 and #3 again. They are quite explicit and a good place to start your understanding. You can also find many books on the basic principles of components, their function and their application - I'd recommend Horowitz's "Art of Electronics" as a VERY comprehensive guide to all you...
  16. kellys_eye

    Cannot connect to my router

    Doesn't that just hack you off at times.....:p
  17. kellys_eye

    Can't get MFRC522 (RFID) to work with PIC18F452 and SPI bus

    The data line is bi-directional. How well does your 'voltage divider' method work when the input to the divider is 'coming from the other direction'?
  18. kellys_eye

    Cannot connect to my router

    You do not need to connect the 3.3V line - just the two GND's between devices and the TX and RX lines.
  19. kellys_eye

    Wanted: Beckman 5k Model A Helipot.

    Is '5k' important? You can often use alternate resistances especially when used in a simple potential divider functions. https://www.elliottelectronicsupply.com/potentiometers/helipot-model-a-c.html
  20. kellys_eye

    Faulty usb-port

    First thing to do would be to refit the USB socket o it can't come loose again - epoxy resin would be a good glue to use (don't get any on or in the socket itself, nor the pins at the back. With the socket secured you can then use solder AND thin wire to solder from each pin to the pcb tracks...
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