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  1. AnalogKid

    Decade counter to Momentary relay?

    The cap will be smaller if you use it to modify the transistor's base current. That is, *before* the transistor. The transistor will turn on more slowly, causing more internal heating. this may or may not be an issue, depending on the power levels involved, the transistor/s package, etc...
  2. AnalogKid

    Digital Space Noise Detector

    Yes. Driving the base with one signal and the emitter with another will produce mixing action at the collector. Heterodyning that didn't suck has been around since 1918. One-tube versions appeared in the 20's, and one-transistor versions in the 50's. Here it is in a typical 6-transistor...
  3. AnalogKid

    Digital Space Noise Detector

    Updated.
  4. AnalogKid

    Digital Space Noise Detector

    I think he means radio frequency noise in outer space. ak
  5. AnalogKid

    Digital Space Noise Detector

    OP stands for Original Poster. Some forums prefer TS for Thread Starter. ak
  6. AnalogKid

    Digital Space Noise Detector

    a) It doesn't matter what I would select. It's not my project and I have no operating parameters. b) Since I have no idea what the intended application is, I have no idea. After seven posts, we still have no idea what you are trying to achieve. We do not know if the white noise bit stream...
  7. AnalogKid

    Digital Space Noise Detector

    In one of his novels, Tom Clancy gets into the encryption of secret communications and using the sun as a source of ultra-random number sequences that are distributed on CD's. I have not done any surfing on this, but I'd guess you can buy such items today - unless they've been supplanted by...
  8. AnalogKid

    Digital Space Noise Detector

    Per an act of Congress in 1984, exactly 0% of that applies to a ***receiving*** antenna. Local zoning ordinances or HOA rules might apply, maybe, but only for non-electronic reasons. And even then it's probably not a problem unless you want to mount it permanently on a roof. DirecTV's lawyers...
  9. AnalogKid

    Basic transistor switch

    You don't say how you determined the value of the base resistor, but it is correct. The circuit should work as intended. As indicated in posts #4 and #5, if the load is a relay coil or some other form of inductor, you should add a suppression diode across it. ak
  10. AnalogKid

    Elenco EK-12A Strobe Light Kit schematic

    Yes. I responded on the other forum. thanks. ak
  11. AnalogKid

    Elenco EK-12A Strobe Light Kit schematic

    I have several pieces of an old Elenco strobe light kit. The PC board is marked: EK-12A Online searching indicates that the kit part number might be K-12A, K12, K12A, etc. The pc board has reference designators (!!!), but I have no schematic, BOM, or anything else that assigns component...
  12. AnalogKid

    Simple Gate driver circuit help needed

    "the same" in what way? Same chip - only you know that. Same size - only you know the size of the board. Same 9 V input - is that from a 9 V battery, an external control signal, or something else - only you know. Same input frequency - we don't know what that is. Same output - we don't know...
  13. AnalogKid

    Help with work to finish my college. Help me please!

    The connection dot to the left of the Q7 base is an error. It is not in the original schematic. ak
  14. AnalogKid

    Help identify SMD details

    Ahhh - Hence the reference designator that begins with X. ak
  15. AnalogKid

    Help identify SMD details

    It would help to know what the electronic assembly is - power supply, FM radio - ? Also, a wider image showing more of the surrounding components. ak
  16. AnalogKid

    BJTs used as spdt

    1. Yes, it is possible with two NPN transistors; or with one NPN and one PNP. 2. The components do not have reference designators, so I'll assume that you mean that Q1 is the one on the left. 3. There are indeed problems with Q2. Among other things, you must eliminate D1 and can eliminate...
  17. AnalogKid

    Constant current circuit

    Don't. A switch is a small part of the full range of MOSFET operations. While a power MOSFET certainly can perform as a switch, that is actually a special case of its actual operation. Conceptually, think of it more as a variable resistor like a volume control, except that the resistance is...
  18. AnalogKid

    Hoping to ID this connector for LED array power supply

    When used for an S-Video connection, the 4-pin mini-DIN connector has two GND connections, but no power or audio connections. The connector itself was around before the S-video standard adopted it, and in other applications the pins can have just about any low-voltage signals or power. The...
  19. AnalogKid

    resistor network amplifier demo video

    Given a constant, low-power signal source, it is entirely possible that connecting multiple speakers differently (series, parallel, etc.) will produce different levels of perceived loudness. This is an example of the Maximum Power Transfer Theorem, and has to do with matching the impedance of...
  20. AnalogKid

    resistor network amplifier demo video

    The video has several problems. First is that it is so poorly drawn that it is difficult to see what the actual circuit is. Another is that it is a simulation, not an actual circuit, and you have no idea how the software implements the characteristics of the components. Example: He says "I...
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