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  1. AnalogKid

    Wall LED Light Brightness Reduction

    The light is powered by a non-isolated, universal input switching power supply. Its job is to maintain a constant current through the LEDs regardless of variations in line voltage, component aging, etc. There are several different circuit topologies that can do this. For one of them - If you...
  2. AnalogKid

    Power supply?

    NOTE that the ground for the +/-15 internal supplies and the ground for the main output are n.o.t the same. ak
  3. AnalogKid

    Power supply?

    Yes. This type of auto-ranging is used to reduce the heat in the pass transistors when supplying high currents at low voltages. Stepping down the voltage input to the regulator can reduce the heat by a lot, maybe 75% in some conditions depending on the auto-ranging circuit design. ak
  4. AnalogKid

    Power supply?

    Per the schematic, the power supply circuit output is completely floating with respect to earth ground. That is, both terminals (black and red) are galvanically isolated from the device chassis and the mains earth ground. In some situations, it is desired for the supply's output to be...
  5. AnalogKid

    Power supply?

    The yellow terminal might be a chassis / earth ground. With everything disconnected and off, measure the resistance between the yellow terminal, some exposed chassis metal, and the GND pin on the line cord. ak
  6. AnalogKid

    Setting up a Common Anode Dual LED with one reference point.

    Delete R1. It acts as a ballast resistor, and the circuit will not work with it in place. Yes, the two LED currents will be different. Cost of doing business. If the two LED brightnesses must be approx. equal, achieve this with component selection. ak
  7. AnalogKid

    Setting up a Common Anode Dual LED with one reference point.

    Here is the basic idea from a post on another forum. In your case, SW1 is replaced by the uC open-collector output pin 16. When the output is open-circuit, there is no current path for D6 so it is off. D7 is lit with current through R4. When the output is pulling low, D6 now has a current...
  8. AnalogKid

    Setting up a Common Anode Dual LED with one reference point.

    If U11 pin 16 is rated to sink the amount of LED current you want without its output voltage rising above 0.4 V, then your circuit should work as is. There is another connection trick that requires one extra diode, but no transistor and only one current-limiting resistor. What is the voltage...
  9. AnalogKid

    Electronics seems like magic!

    I can smell the BS through my wifi. ak
  10. AnalogKid

    Electronics seems like magic!

    The diode is a demodulator, not a modulator. These worked well long ago because there were so few sources of RFI. Cold water pipe as a GND - yes. Barbed wire fence as an antenna - maybe, but not very well; too many parallel paths to GND (fence posts). You don't hear about it because you...
  11. AnalogKid

    Electronics seems like magic!

    There are hundreds of books on electronic circuit design. If you include applications notes, design notes, technical papers, etc., then thousands. Aside from real textbook-type-books, chip vendors have huge online libraries. Analog Devices now includes Linear Technology, and Texas Instruments...
  12. AnalogKid

    Electronics seems like magic!

    They are not different kinds, they are variations of the same theme. The only real difference among them is the percentage of coverage of the shield. ak
  13. AnalogKid

    Electronics seems like magic!

    False equivalence. The first transistor was the size of a baseball. ak
  14. AnalogKid

    Electronics seems like magic!

    Way too much to process. But, some low hanging fruit. Nope. Complained about in the 80's, disproved in the 90's. ak
  15. AnalogKid

    Electronics seems like magic!

    BTW, he *invented* coaxial cable. ak
  16. AnalogKid

    Electronics seems like magic!

    Really? US patents apply to all of the states all of the time. Whether or not the patent holder chooses to enforce restrictions is their choice. You can't "escape" licensing fees simply by moving. "Southern California was also chosen because of its beautiful year-round weather and varied...
  17. AnalogKid

    Electronics seems like magic!

    Edison was a machinist and a botanist. Gates and Jobs were typists. ak
  18. AnalogKid

    Electronics seems like magic!

    Commercial, and particularly visual sci-fi (TV and film as opposed to printed novels) is notoriously fickle. Look at the main, big spacecraft control room in 2001 compared to the one in 2010. It looks like while the storyline advanced 10 years, spacecraft control systems regressed 50 years...
  19. AnalogKid

    Electronics seems like magic!

    Some are, some aren't. What are your expectations based on? Grand sweeping generalizations about technology almost always are incorrect. (Ahhh - but what about grand sweeping generalizations about grand, sweeping generalizations - ?) ak
  20. AnalogKid

    Electronics seems like magic!

    Would you be less disappointed to find out it's only 1 to 5 years behind? ak
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