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  1. kellys_eye

    MIC4609 Mosfet Driver Current spike on Enable

    What about track layout?
  2. kellys_eye

    MIC4609 Mosfet Driver Current spike on Enable

    Which means that only by switching on two fets can you get such a current flow - irrespective of any load connected.
  3. kellys_eye

    MIC4609 Mosfet Driver Current spike on Enable

    Can you hard wire the inputs to disable them and try the enable signal (I like to prove the 'theory' rather than rely on manufacturers assurances). This would prove the driver chip to be the definitive cause.
  4. kellys_eye

    MIC4609 Mosfet Driver Current spike on Enable

    Which means you 'must' have two FETs conducting simultaneously - are the H/L drive inputs at 'indeterminate' levels (i.e. sans pull up/down) when EN is enabled? Could this state originate from the controller rather than the driver?
  5. kellys_eye

    Hi I’m Justin

    'ambitious'.... I like it! We need confident young people to join the site. Welcome.
  6. kellys_eye

    Playing with fire

    I've yet to see any real battery 'event' of any sort...... and I'm not the best at respecting their needs either. Whether it's because I've been lucky (so far!) or haven't appreciated just how much abuse they really can take I'll never know..... Same goes for the 'exploding battery charger'...
  7. kellys_eye

    I never knew.....

    ... that 'manufactured' pcb's could be so cheap and such high quality. Yeah, Mr Luddite speaking...:p or Mr Behind-the-times anyway.... I was browsing Youtube when I clicked on someones instructions for getting a pcb manufactured via JLRPCB (or something like that, could be wrong on the name)...
  8. kellys_eye

    Spark gap transmitter

    There are many legal short-range wireless modules available as well as PMR devices (walkie-talkies) that are licence-free that could be used for the purposes you describe but they aren't straight forward in operation (relatively speaking). This is not a subject for the uninformed therefore we...
  9. kellys_eye

    Switched Mode Power Supply/Switching Power Supply (SMPS)

    Opto couplers provide the isolation necessary between the output (low) voltage and input (high) voltage sides of the system. Their input - the diode side - is a 'sample' of the output voltage which is then fed back to the controller chip to self-regulate the output voltage. If the output is...
  10. kellys_eye

    Switched Mode Power Supply/Switching Power Supply (SMPS)

    The only 'feedback' to the PSU to indicate (or activate) the outputs is the output itself. If you've already loaded the output to check for operation then it's unlikely that load-detection is the method being used. This assumes you're loading it sufficiently...... you could try to load it by...
  11. kellys_eye

    Building a multimeter vs. cannibalizing one?

    No way can you build cheaper than buy these days. Small DC voltage measuring modules can be found for $2 - scaling the input (or adding recitifcation etc) is simple enough.
  12. kellys_eye

    Car ECU think I found the fault?

    I have no idea what the picture you posted is supposed to show....????? Yes, heat can destroy components but some components handle heat better than others whilst others are MEANT to dissipate heat - there are many variables. Show a wider picture of the whole ECU circuit board.
  13. kellys_eye

    Switched Mode Power Supply/Switching Power Supply (SMPS)

    The bridge rectifier won't be the problem. We can go on changing parts 'at random' to no good effect. Try downloading the data sheet for the CM6800 and see if there is an application schematic for it - this could give some pointers on where the fault may exist as many designs are built around...
  14. kellys_eye

    Car ECU think I found the fault?

    How do you know? The only true test of their reliability is a measurement of ESR, something you can't do in-circuit. Standard practice would be to replace all electrolytics in this case. You are right to investigate any suspect heat source and diodes don't normally dissipate enough heat to...
  15. kellys_eye

    Insufficient Power on my Load

    The load itself determines how much power is drawn - you can't 'force' power into a load. When you state a '2W MP3 decoder' what is the actual stated current consumption? Is the '2W' derived from the audio output specification?
  16. kellys_eye

    Car ECU think I found the fault?

    Do you have a full wiring diagram for the engine? Can you show a more complete picture of the ECU? Cut one lead of the diode (leave enough to remake the joint using a soldering iron) and test the diode again - if you feel you must. As above there are usually many other reasons for the engine...
  17. kellys_eye

    Switched Mode Power Supply/Switching Power Supply (SMPS)

    Your meter 'might' show a reading but the output at 8/9 is at a high frequency that most meters can't read. It's points 1,2 and 3 for the primary of the transformer for the 52V supply, again at high AC frequencies so probably not properly measurable using your test meter. If it isn't the main...
  18. kellys_eye

    How do I reduce the speed of a 12v childrens car

    I'd start with a 100k linear pot - that should be enough to prevent loading of the hall effect output but be low enough to allow current draw to the speed controlling circuitry without causing problems. Without full technical details this is going to be a suck-it-and-see situation but the cost...
  19. kellys_eye

    How do I reduce the speed of a 12v childrens car

    No it isn't. That's wrong. Using a new potentiometer, cut the green wire and the bit of green wire that's still connected to the PLUG should connect to one of the outer terminals of the new potentiometer. The bit of green wire that's going off to the controller box should now connect to the...
  20. kellys_eye

    Stepper Motor problems...

    Many car speedometers are stepper diven and there is a range of stepper controller chips (plus the controlling mechanisms to which a pointer can be attached) available on t'internet. Adafruit does one and has all the adetails you need https://www.adafruit.com/product/2424
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