Search results

Search Forums New Posts
  1. chopnhack

    Designing a Time Delayed Relay

    If the board is suitable to send off, my thoughts are starting to shift to the programming of the pic. To that effect I produced a flowchart of what I think is going on with the chip and its gates. I am not sure of the terminology yet, just wanted to see if I was on target with the logic.
  2. chopnhack

    Can you help me indetifying the components? (LED Hourglass)

    Well, E-Bay is your friend! http://www.ebay.com/itm/FK154-Electronic-Sandglass-22-LED-Un-assembled-For-Student-Project-Learning-Kit-/321129433772?pt=LH_DefaultDomain_0&hash=item4ac4ce4aac#shpCntId $17 shipped to Croatia ;-)
  3. chopnhack

    design buck converter with arduino controlling pwm

    Do you mean that you are going to use more than one mosfet? Like in a synchronous design that has an upper/lower gate? or? Where you show V2 is where the Arduino with PWM would go - see this site for some info.
  4. chopnhack

    Testing a electrolytic Cap

    Hey Adam :-) I took a look around and it seems film capacitors are the closest alternative to electrolytic caps. There are limitations though - seems as you get above 700μF or so they don't make film caps (at least I didn't see any in a quick search). This was a good link discussing the...
  5. chopnhack

    Testing a electrolytic Cap

    Good points, but are there any alternatives? I have heard that tantalum caps can be quite dangerous as well.
  6. chopnhack

    Testing a electrolytic Cap

    If you are an elec. enthusiast - you can go this route: http://ludens.cl/Electron/esr/esr.html or E-Bay has a bunch cheap if you can wait on them to come from China.
  7. chopnhack

    Testing a electrolytic Cap

    Your meter won't be able to test that cap - further, the capacity testing of most meters isn't as reliable for many reasons. You would want an ESR of 1Ω or less to claim the cap as capable of continuing service. That being said, I too saved a monitor from an early demise by simply re-capping it...
  8. chopnhack

    Designing a Time Delayed Relay

    Small update with some changes - fewer vias and the physical layout showed that the J2 needed to be moved slightly. Quite happy with the results, very compact!! @KrisBlueNZ - Kris, do I need to include a diode after the inductor? I was reading up on SMPS and on a simple buck circuit, they...
  9. chopnhack

    PCB Design Considerations

    I would like to start a living document of sorts to include the collective wisdom of the forum on PCB design considerations - things to look for and watch out for when doing a PCB layout. General Guide PCB thickness Copper layer thickness Ground Planes -Short article discussing ground plane...
  10. chopnhack

    PCB Design Considerations

    chopnhack submitted a new resource: PCB Design Considerations - Tips on designing PCB's Read more about this resource...
  11. chopnhack

    Beginner question regarding battery charge and circuits

    Diodes could serve the purpose to some extent as they act as one way valves for flow, switches and transistors for that matter too. There is a slight loss across the diode - certainly not the most efficient way to reduce power. Can you elaborate more on what you want to accomplish and what parts...
  12. chopnhack

    Designing a Time Delayed Relay

    Ok, but in this case is the black areas between the copper pours not evident in being the isolation areas? I might be missing your message, sorry. Thanks! :) 70 thou (0.07") between copper pours (high voltage and ground planes. Found a better solution, I think see updated layout. The board...
  13. chopnhack

    Designing a Time Delayed Relay

    It's somewhat academic and to be honest, somewhat prideful - compared to manufactured boards, it looks a bit novice so I was wanting to shrink it as much as possible. From a size standpoint anything under 3.5" should theoretically be fine - the more room now, the better, I still have to stuff...
  14. chopnhack

    List of EDA packages

    Got an email today from DigiKey regarding a new EDA package.
  15. chopnhack

    Designing a Time Delayed Relay

    Wow, I am surprised! I didn't think that it could be shrunk more. I think the point of diminished returns was past some months ago Kris :p:D I can't see ways of making it smaller and still maintaining the isolation zones for the various components so from a novice standpoint I would call it...
  16. chopnhack

    Digging a hole to China

    Nice Dave, that is really cool. I would come out in the Indian Ocean LOL ... no short cut to the factories in Guangdong province! :D
  17. chopnhack

    Designing a Time Delayed Relay

    I was able to consolidate the layout a little more and moved three components to the back side. (The resistor that is smashed between the capacitors is on the reverse side and the two smd caps in blue below). It netted me a 11% decrease in size! 3.17x3.45 vs 3.5x3.5 Given the isolation areas...
  18. chopnhack

    Calculating current through resistors

    Can you elaborate further Steve?
  19. chopnhack

    Dryer not spinning

    Indeed! It was simply the belt :-) I was happy when I heard the machine come to life when I pressed the button. Hope to have the part soon. Thanks all!
  20. chopnhack

    Dryer not spinning

    Thanks Blue - the schematic is what came up for the model Maytag LSE7804ACE - its an older model marked as 3 wire, so its actually 240v (split phase in the states) with ground acting as neutral for the 120v circuitry onboard if there is any - the electronic controller has no LED or electronic...
Top