Search results

Search Forums New Posts
  1. kellys_eye

    Education & Jobs in Electronics

    In business, profit is everything. You're asking what a prospective employer wants from an employee - it's an ability to make a profit for that employer. That's what they want. As @davenn said, you either have theory as your input, practical experience as your input or a combination of both...
  2. kellys_eye

    Education & Jobs in Electronics

    If you can find one, a company that would take you on after an oral examination of your 'supposed' understanding of the subject matter they wanted employers for. In other words, if you try at a company that does bench repairs on audio equipment you would have to demonstrate knowledge of such...
  3. kellys_eye

    Question about op amp dual supply circuit...

    What, precisely, are you using for the power supply? Does it ramp up the +ve and -ve rails at the same rate/instant?
  4. kellys_eye

    Battery Protection from alternator.

    Give us the spec of this alternator. Surely it has an INTERNAL regulator? If it hasn't then what are you using to regulate the output anyway? It's output can only exceed 28.8V if it's either not working or you momentarily disconnect the battery (when you might see a surge higher than 28.8V...
  5. kellys_eye

    Battery Protection from alternator.

    You seem to be very nervous of an over-voltage situation! Not the first post you've put here on the subject. The device you link to does what it does to protect the batteries - not your equipment. If you want your equipment to be protected then ensure it is capable of either operating at the...
  6. kellys_eye

    Quality Pot for Servo

    If ever you need 'quality' from a servo you fit an EXTERNAL pot to the 'lever' that has the most importance i.e. in a ships rudder control system the feedback pot is coupled directly to the rudder stock (shaft). You need a feedback pot with the largest length of track possible to attain good...
  7. kellys_eye

    Lowering AC Motor RPM's

    It was 'tongue-in-cheek' really..... I'm aware that a 7-segment display is the same regardless of its orientation (up/down) if you ignore the d.p. In a world of 'aesthetics' you'd think the manufacturers would be aware of 'polarity'. But, then again, we're talking China here.......
  8. kellys_eye

    Lowering AC Motor RPM's

    Is it me or is the LED display on that amazon speed controller upside down!
  9. kellys_eye

    ATMEL 89C51RD2 ISP, HEX file programming problem

    'Cannot write to port' infers a problem with the interface in your PC. Are you using a real serial port or a USB-simulation? It's a common issue that not all USB-to-serial converters work to the full serial protocol standard and there are recommendations for 'approved' converters that get...
  10. kellys_eye

    High-temperature microcontroller

    Look for Mil Spec (Military Specification) devices. These usually go to 125degC but expect to pay Mil Spec prices too! Easiest way would to fit decent cooling.
  11. kellys_eye

    Output voltage higher than expected

    I'm too close to retirement to be bothered!
  12. kellys_eye

    Looking to update older telescopic antenna to modern one (adapter?)

    The antenna you intend to fit doesn't allow for changes in length or orientation - factors that could be useful when trying to maximise signal strength and/or reducing interference. Seems like a backward step to me.
  13. kellys_eye

    Output voltage higher than expected

    Yes, I meant to type series but somehow didn't realise I'd written shunt! D'oh!
  14. kellys_eye

    Could a Raspberry Pi usefully help me create a wind direction meter with physical/analogue face and hands...

    Your best (only) choice is to use a stepper motor and the associated controlling circuit/software. Adafruit do a small steeper as per this link. https://www.adafruit.com/product/2424 The short video therein shows the needle moving 270 degrees but it is quite capable of 360 degree rotation -...
  15. kellys_eye

    Output voltage higher than expected

    That was my first thought but since the output looks to be via shunt regulation there's no real way the voltage could exceed what the circuit is designed to deliver. I suspect it's a case of misplaced ground probe when metering the output.
  16. kellys_eye

    Could a Raspberry Pi usefully help me create a wind direction meter with physical/analogue face and hands...

    To do it using discrete (perfectly feasible) and/or Raspi components isn't that difficult. You can source what are called 360-degree potentiometers that will deliver a proportional voltage that is readily repeatable either via conversion to a digital signal or used directly in an analogue form...
  17. kellys_eye

    Output voltage higher than expected

    Can't read the schematic - too low resolution.
  18. kellys_eye

    Could a Raspberry Pi usefully help me create a wind direction meter with physical/analogue face and hands...

    Here's the device per the previous post: The main dial is only some 3 inches across but the bezel could be removed and a larger pointer fitted (along with a dial of your choice). Power and connections are made between the two units via the chock block - you need FIVE cores (the device came...
  19. kellys_eye

    Could a Raspberry Pi usefully help me create a wind direction meter with physical/analogue face and hands...

    What about a 'speedo cable' type solution? Mechanical coupling to a chimney mounted vane and reciprocated at the display position? https://www.cable-tec.co.uk/products/speedo-cables/ An electronic solution is fairly easy to resolve - with the right approach and skills - but sometime the KISS...
  20. kellys_eye

    Laptop power supply's capacitor burnout

    In the case of a switched mode power supply, which is presumably what we're referring to(?) the likely dud capacitor could be on the secondary side and the lack of smoothing ability makes the feedback signal (for output regulation) impossible for the switching controller to 'see' properly...
Top