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  1. kellys_eye

    How to boost 2v - 4v, 50mA - 100mA to 5v 500mA?

    If you assume 100% conversion efficiency (impossible) then 10V @ 250mA could theoretically convert to 5V @ 500mA - but it won't in the real world.
  2. kellys_eye

    How long does it take to charge a 500mAh battery with 5V 80mA?

    The battery is 1.85Whr and the charge can deliver 0.4Whr so (assuming zero losses and 100% charge from zero) it would take 1.85/0.4=4.625 hours. With expected losses and other inefficiencies I'd plan for at least 8 hours.
  3. kellys_eye

    Yaesu FT75 manual/schematic required

    Individual file sizes vary from around 1Mb (these upload ok but there are only 2 out of 14 to make a full manual) to as much as 10Mb. As said, 14 files in total and a 'whole file' size of 224Mb. The schematic might be of most use to others so I'll put that here anyway - if anyone wants the...
  4. kellys_eye

    Samsung 50-inch plasma Power Supply Board issue

    No accounting for taste........
  5. kellys_eye

    Samsung 50-inch plasma Power Supply Board issue

    No probs - we help where we can. In many Switched-mode power supplies (as yours is) the output voltage is monitored so it can be regulated by a feedback process and if the output specifications (current or voltage) fall outside a set parameter then the circuitry sees this as a (potential) fault...
  6. kellys_eye

    Yaesu FT75 manual/schematic required

    Nope - most individual pages are still too large!
  7. kellys_eye

    Samsung 50-inch plasma Power Supply Board issue

    Depending on the PSU design it may be that the output requires a load in order to stabilised. 200-ish volts at 10mA (say) would require a load resistance of 20k ohms (and a power rating of 2 watts (use a 5W resistor to be safe). I'm not sure that 10mA is even enough..... so calculate a load...
  8. kellys_eye

    Yaesu FT75 manual/schematic required

    I've now made a pdf of the FT75 manual but it's too big to upload here! Any suggestions?
  9. kellys_eye

    I am deeply involved in making a cockpit for flying with MSFS 2020

    That will be true for a personal experience viewpoint - like a walk-and-talk experience through the pyramids - but when the body is subjected to simulated angles and thrust as found during flight it can't adapt to the lack of 'down' (gravity) hence the sickness issue. You can suffer similar...
  10. kellys_eye

    STM32 & NEXTION HMI SCREEN - SENDING AS CHAR READING AS STRING

    You answer your own question - specifically you use a 'table' where the required information is stored in a fixed location in memory and you then program a pointer/counter to the start of the string and 'count out' the data to the specified port (display).
  11. kellys_eye

    I am deeply involved in making a cockpit for flying with MSFS 2020

    I've always thought the implication of VR/3D goggles was going to 'bomb' because they haven't yet discovered a way to prevent motion sickness in the wearer. Until they develop anti-gravity/inertia generators the user will always be subject to disconcerting anomalies between sight and sense...
  12. kellys_eye

    power supply Pace Sky Digibox 2600

    Many common issue sat receivers have known SMPS issues and there are (or were anyway) kits of parts to replace the 'usual suspects' that were know to fail. Google may be your friend. Ta dah..... https://www.donberg.co.uk/descript/p/pace_kit_11.htm Edit - oops, that the 2200 but it may be...
  13. kellys_eye

    SMPS repair

    De-solder and remove the defective part and fit a replacement observing polarity.
  14. kellys_eye

    Artificial Intelligence

    Call centre staff are a waste of space imho. They only give information that you should be able to access freely anyway. Many that I've called respond automatically, taking every bit of data you can offer including your inside leg measurement then they direct you to an operator who asks the...
  15. kellys_eye

    Inductor Question

    Got any more details of the 3n3 capacitors 'bundled together'? They remind me of a particular version of capacitor well known for their ability to self-destruct.
  16. kellys_eye

    VFD not reaching 50 Hz

    errrr... leave it as DOL? I'm sure I'm missing something here :) Then again, a lightning strike inevitably (in my marine experience) travels a lot further than you'd expect and damage elsewhere seems probable as the symptoms tell us. Something in the feedback circuitry seems the likely place...
  17. kellys_eye

    Gaussmeter dc bias

    Not here - this isn't a summation circuit. Once the op-amp output exceeds the voltage at the wiper of the pot the op-amp voltage becomes the 'dominant' signal. It's more like a 'squelch' setting in that the pot level sets the point at which the op-amp output has to exceed in order for a change...
  18. kellys_eye

    Gaussmeter dc bias

    In this case the op-amp output would only have an effect if/when it exceeded the DC level set by the pot - thus a bias.
  19. kellys_eye

    Artificial Intelligence

    I suppose the true test of AI is to compare their outputs as, since the truth (scientifically speaking) is theoretically fixed the outcome should always be the same. Unless we give AI actual access to do physical things I doubt its opinion will count for much unless there are people who will...
  20. kellys_eye

    Gaussmeter dc bias

    What's to calculate? It's a pot (presumably linear law) across a 5V supply therefore the voltage at the wiper will be directly proportional to its position. Assuming a 10 turn pot (common) you get 0.5V per revolution all the way from 0 to 5V. Or am I missing something?
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