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  1. kellys_eye

    ECM - Jeep computer - help IDing the motherboard please.

    Honestly pal, chum, cobber, fella, I'm not actually against what you're trying to do. We all have a vested interest in knowing how things work and would be more than eager to accommodate your needs but regardless of the pictures you might get to post the end result will remain the same. The...
  2. kellys_eye

    Radio transmitter, options for reducing harmonic emissions

    Yes, harmonics. A 'wideband radio' is not a suitable test measurement device. You need a spectrum analyser to properly observe the 'crap' you'll be putting out and, believe me, crap is what's happening.
  3. kellys_eye

    Radio transmitter, options for reducing harmonic emissions

    Get hold of a copy of the ARRL Handbook - their explanation of the theory behind RF transmission is excellent. They also have schematics for simple and LEGAL transmitter circuits, explaining the requirement for cleanliness of signal (i.e. low harmonics) etc.
  4. kellys_eye

    Radio transmitter, options for reducing harmonic emissions

    An RC filter for RF??? What frequency are you actually hoping to operate on? The oscillator (your astable mutivibrator) should be set to match the resonant frequency of the inductor/capacitor that forms the tuned circuit operating at the chosen frequency. You don't have any suitable...
  5. kellys_eye

    Wall heater went out

    Thermal overload. Some have auto-resetting protection devices, others have thermal 'fuses' which need to be physically replaced. Some may even have both...... The thermal fuse devices look like little silver 'sausages' with wire ends and are normally crimped into the circuit (soldering causes...
  6. kellys_eye

    Arduino based frequency counter design

    TBH there are already a number of frequency counters available that do the same job but with less component count and lower cost. Undoubtedly cheaper too. Not to distract from the design - I appreciate the work put into it - but you're kind of re-inventing the wheel.....
  7. kellys_eye

    Firelite ms-5ud

    Equipment site: http://www.firelite.com/en-us/Pages/Product.aspx?category=ConventionalFACP&cat=HLS-FIRELITE&pid=ms-5ud Manual: http://www.firelite.com/CatalogDocuments/52626.pdf although the OP could have done this in advance........
  8. kellys_eye

    Help finding an AC Adapter

    Show the label on the existing power pack.
  9. kellys_eye

    60 Hz line frequecy divided to 1 pps

    Here in the UK the standard line frequency is 50Hz guaranteed to gawd-knows-what accuracy but over a specific time interval only. In other words the accuracy can vary at any specific instance but over a specified time interval the errors must cancel out to ensure the overall stated accuracy...
  10. kellys_eye

    Identify smd inductor

    I take back what I said about it being part of an SMPS circuit...... It appears that you've applied reverse power at some time and the positive line has - somehow - found a way back to ground via T1 and burned the winding. Given that the inductors presence isn't 100% essential you could simply...
  11. kellys_eye

    ZIF-sockets from eBay etc -quality OK?

    I've had the 40-pin versions from our 'industrious neighbors' and found them to work fine.
  12. kellys_eye

    ECM - Jeep computer - help IDing the motherboard please.

    The image isn't clear enough to do positive identification. What make you think you can do a better design job than the muti-billion-backed companies (Jeep) that created the original? Updating the EPROMs means removing them and placing them into an EPROM programmer and re-writing the contents.
  13. kellys_eye

    Arduino based frequency counter design

    4MHz isn't a VHF frequency.......
  14. kellys_eye

    Smd ics and through hole ics

    Yes of course it can - it's often awkward to make the physical connections but there's no other reason why you can't use one. Certain exception may be made at high frequencies whereby extended lead lengths (from DIP to SOIC pads) may introduce issues but the SMPS chip you isn't likely to be...
  15. kellys_eye

    HealthKit Scope Model 0-8

    What do you mean 'clean'? Can you post pics of the trace?
  16. kellys_eye

    Treadmill NordicTrack Elite 4000

    Sure the Treadtracker is working ok? It's not slipping? It hasn't got a worn wheel or some crud around it etc? The only other thing that can change the speed is the feedback sensor on the treadmill itself. The drive motor might have a slotted opto-coupled disk to report its speed back to the...
  17. kellys_eye

    DC Actuator problem

    That is, as you say, just 'inertia' - providing it doesn't carry the movement beyond what's allowed (i.e. it hits some form of physical obstruction) then there's not a lot to be done about it. I don't really follow when you say: is it MEANT to stop 'momentarily' or is it mean to stop...
  18. kellys_eye

    Identify smd inductor

    If the inductor has shorted it's likely that the driver device has gone short too - plan to change that as a well.
  19. kellys_eye

    Radio transmitter, options for reducing harmonic emissions

    You have to account for output filter losses when you design for a particular power output requirement. Designing a circuit and THEN expecting to add harmonic filtering without considering the losses it introduces is just.... wrong. Can you post a schematic of the circuit you have to date...
  20. kellys_eye

    Current limiting in a CC/CV power supply

    What is your point? You make these repeated 'contradictions' of my post yet offer nothing to the thread or any explanation of why you think a regulated power supply isn't 'good' when it has a constant output voltage. I'm not referencing 'constant current' - I'm talking about a REGULATED POWER...
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