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  1. KrisBlueNZ

    need a mentor

    Also tell us what aspects of electronics you're interested in. Microcontrollers? Audio? Music? Radio? Motors? Lighting? etc.
  2. KrisBlueNZ

    simple fm receiver

    What did you use for C and L?
  3. KrisBlueNZ

    Help for breadboarding components

    Yes, USD 150 is pretty steep, and the tindie.com board looks like it will do everything the LTC demo board does!
  4. KrisBlueNZ

    Help for breadboarding components

    Low switching frequency doesn't mean slow edges. These inductors range from 7.5 µH to 25 µH. That normally corresponds to a pretty fast dV/dT. I'm not very familiar with these devices so I could be wrong, but I don't think breadboarding is suitable. I expect Linear Technology offer an evaluation...
  5. KrisBlueNZ

    Help for breadboarding components

    The LTC3108 operates with very fast switching times and a breadboard is not really suitable for prototyping it. If you really want to do this, I'd suggest that you mount the transformer upside down onto a piece of stripboard or pad array board, and solder wires to the SMT connections or bumps...
  6. KrisBlueNZ

    bathroom door automation design - grab a coffee first!!

    Sure :) I'm a bit strange... I actually LIKE documentation! Cool. That should be an interesting learning experience for both of us. Well, you've written some very detailed and pretty clear specifications and messages on this thread. I think you just need to organise your thoughts into a...
  7. KrisBlueNZ

    bathroom door automation design - grab a coffee first!!

    Yes, some kind of timing circuit. Relays, driven by transistors, with delays implemented with resistors and capacitors. Logic ICs can be used to perform logical functions such as AND and OR, and latching. Well... I can point you to an example: a Whac-a-mole circuit I designed (just for fun). It...
  8. KrisBlueNZ

    PWM output mirror??

    Hi there and welcome to Electronics Point :-) Connected WHAT to the buck circuit? Please start by posting the schematic of your buck regulator.
  9. KrisBlueNZ

    Sensitive microphone

    Hi Brendon and welcome to Electronics Point :-) I think you need to start by choosing microphones. If you want low noise, well-defined frequency response, and well-defined directionality, you can't use those little electret microphones; you'll need some proper microphones. Measuring sound...
  10. KrisBlueNZ

    bathroom door automation design - grab a coffee first!!

    Wow! That diagram is priceless! You should win an award for it. Especially the yoga lady hitting the emergency release button! And your description in post #1 is pretty clear too. There's heaps of detail there, but I want to go through your requirements just to make sure I understand them. You...
  11. KrisBlueNZ

    Motion sensor lighting with a difference

    themalloy, what's happening to this project? Have you made any progress on the proximity detector?
  12. KrisBlueNZ

    Designing a Time Delayed Relay

    OK. I'm with you so far... So each wall-mounted box, with power receptacles for your equipment, will have one of these circuits mounted permanently inside it? I had already assumed that. OK, you've lost me here! Are you planning to put two of these boards in each box, so each box will have...
  13. KrisBlueNZ

    Replacement for a microcontroller

    OK, here's a test setup for the CD4046B that you can build up on breadboard or stripboard to get an idea of what it does and whether it will be useful to you. The VCO in the 4046 is a voltage controlled oscillator. This means that it generates a signal (a tone) at a frequency that is...
  14. KrisBlueNZ

    built in self test

    It seems like there's a lot of information about VLSI built-in self-test: http://lmgtfy.com/?q=VLSI+built+in+self+test
  15. KrisBlueNZ

    Circuit Help !!!

    Well, try increasing the current limit a bit more. Try 300 mA.
  16. KrisBlueNZ

    Why am I able to use a dc wall wart instead of an ac one to charge my lawn mower?

    It's possible that the DC supply would charge the batteries. I doubt it would charge them fully. Whatever reported that they were 3/4 full may have been wrong. I don't know why the charging indicator didn't light up when you used the AC supply. Do you think it isn't charging at all? Check the...
  17. KrisBlueNZ

    Circuit Help !!!

    The circuit takes less than 10 mA once it has started up. It may draw a lot more than that for a short time when you connect it to the power source. Have you tried a 4700 µF capacitor across the power supply and powering the circuit up? Did it work? Yes, you can try increasing the current...
  18. KrisBlueNZ

    Why am I able to use a dc wall wart instead of an ac one to charge my lawn mower?

    Hi Tom and welcome to Electronics Point :-) The board inside the mower will include a bridge rectifier on it. When you plug in an AC plugpack, this bridge rectifier will convert the AC to DC so it can charge the batteries. (There will probably also be a smoothing capacitor after the bridge...
  19. KrisBlueNZ

    Help with timers

    Hi Brad and welcome to Electronics Point :-) If it's a safety feature, then you shouldn't be disabling it, right? It may also be designed to protect the heating element against burning out; I don't know. Also, do you know how much power it would draw if you kept it running 24/7? I do know that...
  20. KrisBlueNZ

    please identify this component

    It's a SOT-223 package. The stylised 'F' logo is Fairchild (http://www.fairchildsemi.com). The markings seem to be "DF45 A56" and I couldn't find those using SMT package top marking searches. It's most likely either a MOSFET - one of these...
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