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  1. kellys_eye

    Hide IR receiver in project box

    There are a number of IR-transmissive materials - some that even appear opaque - and ISTR some handheld project cases that are 'totally' IR transmissive (i.e. the whole case is made of that material. Look at any IR receiving unit you have at home - there will be many - and take incentive from...
  2. kellys_eye

    Cost effective prototyping for testing components

    Why test them? They have predictable parameters as per their data sheet so if those values meet your requirement then simply use them. Are you expecting them to be problematic? If so, in what way? The alternative would be to make your own adapter boards and fly leads.
  3. kellys_eye

    Audio Circuit Collection

    Just checked my old HDD and found a folder that's labelled "9365 Audio Schematics and Service Manuals" which I'd love to post here but it's 17Gb !!!
  4. kellys_eye

    Help needed on portable battery project

    If you're going to use anything more than a few 10's of watts for any length of time then forget all the solar/wind crap and just get a small portable generator. A small (<1kW) inverter/generator costs less than £200 and will run for hours at low load on a single tankful. It will also provide...
  5. kellys_eye

    Microcontroller and A9G module

    You'll spend more time (and money) making your own development board than you ever would by purchasing one ready-made. Put your original purchase down to 'experience ' (a bad one!) and try to resell it to someone who either has more time/money than you and/or less of a clue (now)!
  6. kellys_eye

    12V/5A from 19.5V/4.6A laptop charger

    ...that are inevitably OVER-RATED as to their capabilities.
  7. kellys_eye

    Large motor start up

    If you are controlling a motor for a boat you will want a variable control. SImple on-off won't give you much in the way of control which is why the MOSFET PWM method would be the way to go. It doesn't really matter what voltage/current you are faced with - properly designed it WILL work...
  8. kellys_eye

    Microcontroller and A9G module

    Ooops.... you should have got the development module/board rather than the bare module. Get the datasheet for the device or for the development board. To use it you need to connect a SIM card and the development boards come with them fitted/interfaced plus all the required I/O ports made...
  9. kellys_eye

    Led grow light diode replacement help

    That's more the case - they certainly don't consume 1200W themselves!
  10. kellys_eye

    Led grow light diode replacement help

    Five drivers (each 50W?) = 250W total available. 120 LEDs. Maximum power PER LED is 250/120=2 (as near as we need) so the absolute maximum per LED (assuming they are all identical) is 2W. They look - to me - like 1W LEDs though - something like these...
  11. kellys_eye

    Hi, can somebody help me with feedback circuit

    The resistor and inductor associated with C1 are representative values (parameters) for the losses in C1 and allow you to make a more accurate calculation for resonance and/or Q. Same applies for the resistance associated with L2.
  12. kellys_eye

    Led grow light diode replacement help

    If there is only ONE driver unit (the one labelled 50W) then each LED will have a power of 120/50 or approximately 0.5W (to be on the safe side it is recommended that you use somewhat LESS LED wattage than the driver can provide so, more accurately speaking, the LEDs should be nearer 0.3W or...
  13. kellys_eye

    Led grow light diode replacement help

    How many LEDs are there in total (including all the burned out ones)?
  14. kellys_eye

    Large motor start up

    A PWM motor drive using MOSFETs would work - if designed properly. It would make an ideal 'accelerator' for a boat motor. Got any information on what you used previously? You can get these on eBay...
  15. kellys_eye

    Led grow light diode replacement help

    Got any pictures? Your question is 'meaningless' without them.
  16. kellys_eye

    Large motor start up

    Why use a 'cheap' relay when you're expecting 60A+ to flow? You're talking 'car starter motor' type currents and the solenoid from one would handle that kind of current quite easily. MOSFETs would equally work well but have to be 'driven' correctly. What process did you use to drive yours...
  17. kellys_eye

    Endoscopy Light Source

    Total internal reflection. Google 'fibre optic principle'
  18. kellys_eye

    Swan mark 2 vintage HF RF amp.

    Is there a known 'fault' with the amp/PSU? or are you just 'renovating'?
  19. kellys_eye

    Swan mark 2 vintage HF RF amp.

    If they are still soldered to the shunt then they WILL show 0.00Ω - you need to remove them from the shunt to do a proper resistance check.
  20. kellys_eye

    Low-Profile Temporary Metal Rivets

    There are also these type of inserts: I use them a lot for mounting monitors in my workshop - the hex head (standard metric thread inside) allows you to get a real good tight fit (giggidy).
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