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  1. kellys_eye

    Replacing Large PCB Pin-Headers/Eurocard?

    If you can justify the expense of a solder pump station then do it. But simply cutting the leads, desoldering them (apply heat until they loosen, then pull) then using solder wick with added liquid flux will remove the remaining solder from the holes and leave a nice clean result. All the...
  2. kellys_eye

    RF Circuit Battery Efficiency

    Indeed - the datasheet tells you everything you need to know about using the device - how to connect it, how to calculate the component values etc. You can also 'cheat' and Google the device and search the 'image' results for examples of working circuits others have built. Indeed there are...
  3. kellys_eye

    What is this?

    A multimeter won't help. The insides could be 'anything' - literally - and no amount of multimetering would reveal the contents! There are some 'IC detector' tools around that can decipher unmarked and in-house marked devices but they all assume that they'll have a reference copy in their own...
  4. kellys_eye

    LED stripe resistor

    Of course it's not outputting a 'fixed' 12V - that's the whole point of a PWM dimmer - the average DC output varies as a function of the pulse width however the 'peak' voltage still remains at 12V hence the LED will always have sufficient forward voltage to conduct (emit). Current is still...
  5. kellys_eye

    Power supply problem

    Temporary confusion resolved, normal service is resumed.... If the 12V, as measured, remains at 12V (or thereabouts) then it isn't a problem with the supply being 'man enough'. If the supply wasn't man enough the voltage would fall. What can affect operation is excessive ripple (and it will...
  6. kellys_eye

    LED stripe resistor

    There was never any suggestion or recommendation that they should be. Your assumption seems to have added enormous confusion to the thread.
  7. kellys_eye

    What is this?

    Hmmm in-house marking. Unless we have a Korea Data Systems member on here the best you could would be to ask the manufacturers directly or hope someone comes along and recognises it. One site says it's this: 60V Complementary PowerTrench MOSFET but that's just as a result of the 'nearest...
  8. kellys_eye

    Power supply problem

    Nope - THIS board... You say this board gets 12V and plugs into the mobo to provide the 5V supply too..... the board MUST, therefore, have some conversion circuitry on it and I believe the mobo isn't booting because it either isn't getting the 5V it requires or the 12V supply is pulled low...
  9. kellys_eye

    Power supply problem

    Looks like a 'bulging' capacitor here - the one with 'crap' on it....... can you confirm? If the top IS bulging - change it. What does the connector adjacent to it supply power to?
  10. kellys_eye

    Power supply problem

    I want to see this PSU - photo's both sides please!
  11. kellys_eye

    What is this?

    me neither.....
  12. kellys_eye

    Power supply problem

    If the adapter board takes 12V and then feeds 12/5V into the mobo then there's some form of power conversion circuitry on the adapter board..... show us close up pics of both sides of the board please. It is not possible to determine if the 12V supply is being dragged down or the 5V is doing...
  13. kellys_eye

    4-20ma signal output based on 12 hour clock

    Given the 4-20mA interface usually requires some form of input signal - and that can be 'any' type of signal - it's surely only a means of scaling the input accordingly? A stepped ramp with 720 steps (call it 1024 but resetting at 720) could be built feeding an R2R ladder and used as the input...
  14. kellys_eye

    vu meters diy

    I most certainly wouldn't make fun (knowingly) of anyone's physical or mental deficiencies - your typed responses don't offer any clues and my psychic abilities are lacking :D - however I apologise unreservedly if you feel that I was doing so deliberately. That particular comment was borne out...
  15. kellys_eye

    Power supply problem

    If it's a standard motherboard (looks like it) then where is the 5V supply it will require? The 12V supply seems correct - supply voltages have allowable tolerances of up to 5% so anywhere from 11.4 to 12.6V would be fine - but without the 5V supply the mobo won't work at all.
  16. kellys_eye

    Newbie, please help

    ...standard operating practise here in the kellys_eye household....
  17. kellys_eye

    LED stripe resistor

    0.35A to 0.4A per metre - times 10 metres = 3.5 to 4.0A (and times 12V = 42W to 48W total power). The 50W power pack is too close for comfort. Get a 75W or 100W (the price difference isn't that great). Then check out the same site for LED dimmers such as this...
  18. kellys_eye

    Ultrasonic Water Level Sensor design

    You can either 'up' the transmit power or increase the sensitivity of the receiver. But since the linked-to devices have a working range of up to 6m, you're looking at a rather large tank if you can't measure water content at that range even with the closed-top version fitted. In lieu of the...
  19. kellys_eye

    Critter Zapper

    A mains transformer is good for 1.5kV pulses - sufficient to deter over a small area and definitely for the 'box' the OP wants to protect. Raccoons can probably read better than the low life's that broke into your garage....
  20. kellys_eye

    Got anything new?

    There's probably already something in existence for anything you try to image but the fun in building something that is unique still tasks me. I have a little 'book' of ideas that require motivation to bring to a finished product but also some ideas that I'd considered that may already in...
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