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  1. AnalogKid

    DC Power Supply - Choke for regulated power supply

    A transformer with a secondary rating of 18 Vrms can drive a regulator with an 18 Vdc output. Depending on the output current, the bulk filter capacitor might be a bit large, but nothing extreme or expensive.
  2. AnalogKid

    DC Power Supply - Choke for regulated power supply

    What is the transformer AC secondary voltage (RMS or peak to peak)? What is the load current? You probably are using a 78xx regulator (or one of is derivatives). Consider using an LM317. It is a little bit more complicated with the two output setting resistors, but it has a lower noise...
  3. AnalogKid

    Solar powered balloon?

    The flatter the disc, the less space-efficient it is. Per calculus-1, nothing has a better volume-to-surface area ratio than a sphere. ak
  4. AnalogKid

    Solar powered balloon?

    Or leave the hydrogen alone and compress/expand air in a tank of some kind. We could call it a ballast tank. If it works for the balloon, the navy might be interested. But seriously, the US milirary already has balloons they teather above an operations area for sensor surveillance and comms...
  5. AnalogKid

    Analyse output from laptop charger

    Companies often change power supply vendors, and sometimes non-essential details like the shape or color change. I have three "identical" true Dell power supplies, identical outputs, three different sizes, two different line cords. ak
  6. AnalogKid

    PCB Footprint Question

    The pin spacings are what matter. If they are in reasonably nice, round numbers in inches, then go with that. If you have a part that is native in mm, like a metric header with pins that are 2.00 mm apart or 0.7874", go with metric. Everything about the connector body, seating plane...
  7. AnalogKid

    IR Switch Trigger in Specific Setup

    Yes, my bad, oops. Somehow I thought the LEDs ran on 24 V. ak
  8. AnalogKid

    IR Switch Trigger in Specific Setup

    Relay module that will work as the interface between the sensors and the LED power source. http://www.ebay.com/itm/24V-1-Channel-Relay-Module-Low-Level-Trigger-Relay-Expansion-Board-/191364872003?hash=item2c8e3c3743:g:Y0IAAMXQ74JTT-M4 ak
  9. AnalogKid

    IR Switch Trigger in Specific Setup

    Sorry, I drifted into building the inverter from scratch. Are you looking to build a circuit, or connect together pre-made modules? IOW what is your electronics skill set? ak
  10. AnalogKid

    dimmers?

    Not that I've seen. As long as the input AC powerline is reasonably symmetrical, the energy conducted by the TRIAD curing the positive and negative half-cycles will be equal and the net transformer flux will be zero. An asymmetrical failure in the trigger circuit is very rare. ak
  11. AnalogKid

    IR Switch Trigger in Specific Setup

    The inverter already has power switching parts; better to let them do the work than to add more power switching parts between the inverter and the LEDs. If possible, it would be good to use the output from the body sensor to turn the inverter on and off with its shutdown control pin - if it has...
  12. AnalogKid

    dimmers?

    A TRIAC has a minimum voltage drop across it that can be 2 V or more even when the dimmer is set to 100%. If the triac is in series with a low voltage secondary, that voltage drop might be a problem for whatever is downstream. If the TRIAC is in the line voltage primary, then a possible...
  13. AnalogKid

    ultrasonic sensor at 40 KHz

    Crystals do not like DC bias. The transmitter waveform should be 50% duty cycle. Again, datasheet, page 16, Figure 27, left half (AC distribution amplifier). See post #6. http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tl081&fileType=pdf ak
  14. AnalogKid

    Fuzz Pedal Problems.

    There is no LED in the schematic. ak
  15. AnalogKid

    Opamp vs Comparator

    As you can see on the schematic ... uh ...
  16. AnalogKid

    Finding the smallest possible actuator, or a new solution. Help massively needed!

    What is the minimum travel distance required? What is the minimum required force that the traveler must apply to whatever it contacts? ak
  17. AnalogKid

    Fuzz Pedal, adding a fuzz pot?

    The fuzz pot in the lower right corner of your drawing is connected the same way: 1 - GND 2-capacitor to GND 3- circuit (M2 emitter) Note that your circuit is more of an overdrive than a fuzz circuit. ak
  18. AnalogKid

    Help to solve Operational amplifier

    http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/opampi.html http://research.cs.tamu.edu/prism/lectures/iss/iss_l5.pdf
  19. AnalogKid

    Bench Power Supply

    BTW, that diode arrangement is part of a ring modulator, used for frequency-division multiplexing of multiple voice channels onto one wideband telephone line. As a spinoff, it was used in early voice scramblers. https://en.wikipedia.org/wiki/Ring_modulator ak
  20. AnalogKid

    Help to solve Operational amplifier

    That is incorrect. This is not a power supply. The output signal cannot be greater than the ssupply voltge. Is this homework or school related?
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