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  1. AnalogKid

    Rain gauge resetter

    Another option is a bigger battery. A fat 3.6 V LI cell could last a year. How many battery changes do you do in a year? ak
  2. AnalogKid

    Circuit recommendation?

    1. Total how many yellow LEDs and how many blue LEDs? 2. What is the power supply voltage? 3. Both names flash together, or alternate? ak
  3. AnalogKid

    Ring Doorbell

    This thread is over three years old. Better to start your own thread with the details of your particular question. ak
  4. AnalogKid

    Quick n Dirty answer needed

    The battery is the only power source. Attaching power and GND symbols to it tells the schematic software to connect it to the Vcc and GND pins of any ICs with those pins visually suppressed. This has to do with the way the schematic data is transferred to pc board layout software through a...
  5. AnalogKid

    Quick n Dirty answer needed

    Use the reference designators to tell us which LEDs (and other parts) you have in the circuit. Note that as you add LEDs in series, the minimum operating voltage goes up. Depending on the exact LED part number, each LED adds approx 1.8-2.0 V. AND - If you have only one LED in a string, you...
  6. AnalogKid

    Quick n Dirty answer needed

    First pass at a schematic. Flash rate is 1 Hz; adjust R1 to change. C2 is for power source decoupling, and should be as close as possible to 555 pins 1 and 8. It is shown on pin 4 because that is a convenient place to tie it to Vcc. Many schematic programs hide the power and ground pins for...
  7. AnalogKid

    Quick n Dirty answer needed

  8. AnalogKid

    Quick n Dirty answer needed

    The video segment you posted is for one (1) LED, not 20. That is a significantly different problem. What is your skill set for wiring together all of the parts? This can be done with a single bipolar 555. The forward voltage for a typical red LED is around 1.8 V. Electrically you could have...
  9. AnalogKid

    Quick n Dirty answer needed

    Your question still is not clear. When you say: "Inside the heart, I'd like to have my wife and my initials. I am thinking the initial should flash" are you talking about drawing the initials with strings of LEDs, or backlighting the initials printed on paper, or something else? ak
  10. AnalogKid

    Quick n Dirty answer needed

    I'm discussing the circuit the TS asked about. ak
  11. AnalogKid

    Quick n Dirty answer needed

    No changes are needed - maybe. 1. There is no current-limiting resistor in series with the LED, so the LED should be much brighter. 2. The blink rate is about 60 times slower than it should be for the components in the video. 3. The chip in the first part where he is connecting jumpers...
  12. AnalogKid

    CCTV CAMERA LINGO

    Correct. Original NTSC has 262.5 lines per field, interleaved into 525 lines per frame. There are 21.5 lines in the vertical interval, and that sets the *vertical* resolution to approx 480 lines. Each horizontal line is continuous sweep, so its resolution is set electrically by the bandwidth...
  13. AnalogKid

    CCTV CAMERA LINGO

    From back in another life ... TVL, television lines, is a semi-subjective measure of the maximum image resolution ***in the horizontal direction only***. Vertically, resolution is fixed by the number of scan lines in a frame. Horizontally, resolution is based on the signal bandwidth - the...
  14. AnalogKid

    1-bit magnitude comparator.

    Please post your schematic. ak
  15. AnalogKid

    DC Voltage Control from Solar Panel for direct usage

    A solar panel is an imperfect voltage source. That is, its output voltage sags as the load current increases, but more than it would with a "true" voltage source such as a regulated power supply. If possible, increase the load on the panel in stages and see what the output voltage is with 1 A...
  16. AnalogKid

    Frustrated

    It might be blinking very fast because of a resistor value error. If you have one, replace the timing cap with 10 uF = 22 uF and see if the circuit blinks. Also, there is no power supply decoupling capacitor(s). ak
  17. AnalogKid

    Understanding my mysterious power supply

    One addition to HK's excellent instructions: When applying a short across the power supply output to set the current limit, make sure to use a wire size that can handle 5 A continuously. At the lower currents almost anything will work, but at 5 A a skinny little 24 gauge hobbyist clip lead...
  18. AnalogKid

    Phase Shift Oscillator Puzzle

    I've always preferred the lowpass version of the phase shift oscillator. Better behaved, and a lower distortion waveform available. ak
  19. AnalogKid

    Momentary Switch Bypass

    It looks like all of the brains are on the small vertical pc board you show edge-on. A full view of its front side would help. The switch is SPST. You forgot to mention the LED on the switch board. As a guess, the three wires are GND, LED power, and Switch out. When you press the button...
  20. AnalogKid

    Need help understanding this circuit

    The two rows of pins in an 8-pin DIP (dual-inline package) are 0.3" apart. That means that with the perf-board he is using, there are two rows if unused holes (with copper pads around each one) between the rows of pins. Rather than run a wire from pin 1 to pin 8, he is using globs of solder to...
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