Recent content by pgib8

  1. pgib8

    How is it that so many wireless signals

    What happens when you add more and more signal to an area, for example a standing wave in one spot that you keep making stronger, will the fabric of space tear? I think kind of yes. I guess the field can get so strong that the electrons are ripped away from the atoms, creating a plasma, which...
  2. pgib8

    I'd like to know how put a digital sound bite on a component

    You have a digital to analog converter in your microcontroller and you have a long list of output levels (samples) that are like notes and represent your sound. This long list could very well be stored in internal flash. At discrete time steps the microcontroller loads the next sample. The...
  3. pgib8

    Unbalanced super capacitors in series

    Thanks Herald. What you are saying about the leakage is also the way I understand it. The leakage is like a resistor across that capacitor. This will place a greater share of the voltage on the other one. Like you said in the worst case scenario with 100% leakage is essentially bypassing one of...
  4. pgib8

    Unbalanced super capacitors in series

    Currently my theory is that the leakage will increase with voltage so that they will never reach a 0V to 4V imbalance; but if I'm wrong then it would just be a matter of time before one cap will be at 4V and the other one at 0V :eek:
  5. pgib8

    Unbalanced super capacitors in series

    Here is a formula from this page https://www.tecategroup.com/products/ultracapacitors/ultracapacitor-FAQ.php I don't think it's correct. Vcap1=Vsupply x (Ccap1/(Ccap1 + Ccap2) Assuming Vsupply=5.4V Vcap1=5.4 x (12/(12+9)) = 3.08V In this formula the capacitor with the higher capacitance is...
  6. pgib8

    Unbalanced super capacitors in series

    I'm not looking for advice on how to balance them, so far I'm only reading the same stuff I read online. How far will the leakage take the imbalance, what are the long term effects (no balancing circuit applied), will they reach equilibrium? Bonus: Describe the difference in the way variation in...
  7. pgib8

    RFID Chess Board

    I like the idea a lot but I think it would be too expensive. How about using capacitive touch type technology. The person has to set up the board correctly but once they get going you could have one large PCB detecting when a piece is picked up and where it is dropped off.
  8. pgib8

    Unbalanced super capacitors in series

    Something new to me is that when you put 2 (or more) supercaps in series that one of them could reach a higher voltage than the other and possibly exceed its rated voltage. It appears there are 2 mechanisms by which this happens, one is variance in capacitance and the other is variance in...
  9. pgib8

    Programming starting point

    i start by installing the tools and get to the point where i can even load a program onto the chip. next i work on the startup code, ensuring proper clock selection and what not. that's how i start. after that i take it one step at a time. we're probably talking about embedded programming here...
  10. pgib8

    SPI to UART converter.

    you can bit-bang a uart port yourself and for that you can use any pins you want. the rx pin however ideally will have interrupt capabilities (but also not necessary). it will be more work to do but if you gotta do it you gotta do it. this is not like a hardware uart port that you can just write...
  11. pgib8

    Pi/L filter versus impedance matching network the same?

    Hi everyone. I'm familiar with impedance matching of antennas via a series element and a shunt element but i'm not familiar with filters. When I look at the two side by side they look exactly the same. For instance I used from the source to a 3.3pF series capacitor followed by a 12nH shunt...
  12. pgib8

    Math Question, How Do You Really Figure This Out

    @Audioguru, I took the forward voltage from the datasheet and I understand it's an approximation. @Harald Kapp, I definitely realized that. I posted the picture anyways to show what the wrong thing looks like (don't ask me why) :) Here is a better one:
  13. pgib8

    Math Question, How Do You Really Figure This Out

    No I did not, there only will be one LED. For me this was more of a theoretical question. In praxis there is extra margin which will absorb any variance, including temperature.
  14. pgib8

    Math Question, How Do You Really Figure This Out

    It wasn't really so much about LEDs but the math problem. Both Harold Kapp and Ratch provided excellent answers. Since I'm not very good at math, I was wondering if there is some simple trick, which now I see there is :) That's cool. I actually wasn't sure that if I keep repeating my method if...
  15. pgib8

    Anyone have any oscilloscope recommendations?

    Highly recommend OWON SDS series. It's not a Mercedes but a heck of a lot of bang for your buck. It's a little more than what you want to spend, I think $350ish but worth the investment. One of the features that I love about it that many other scopes don't have is the optional battery (which I...
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