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  1. 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...
  2. 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...
  3. 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
  4. AnalogKid

    Elenco EK-12A Strobe Light Kit schematic

    Yes. I responded on the other forum. thanks. ak
  5. 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...
  6. 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...
  7. 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
  8. AnalogKid

    Help identify SMD details

    Ahhh - Hence the reference designator that begins with X. ak
  9. 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
  10. 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...
  11. 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...
  12. 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...
  13. 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...
  14. 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...
  15. AnalogKid

    LED strobe with fading effect possible with a NE555 ?

    BTW, here is a link to the original page for this circuit. http://www.cappels.org/dproj/simplest_LED_flasher/Simplest_LED_Flasher_Circuit.html ak
  16. AnalogKid

    LED strobe with fading effect possible with a NE555 ?

    I like this circuit because it gets double-duty out of the timing current; storing it up in the timing capacitor for the delay, and then dumping it through the LED. A standard 555 circuit wastes its timing current. There is a way around that, but the flash profile will not have the same look...
  17. AnalogKid

    CD4017B has the jitters

    That looks like it has the driver transistor and transient protection built-in. You might be able to eliminate R2 and T1 in your post #1 drawing. Link to vendor page? ak
  18. AnalogKid

    CD4017B has the jitters

    The output of a TV remote is *not* a simple on/off LED. It is a series of short bursts of a (approx.) 38 kHz square wave. The bursts vary depending on which button is pressed. Your circuit probably is responding to the bursts, which explains the chattering. However, your circuit does not...
  19. AnalogKid

    Not working 12v dc to 220v Ac

    The only thing limiting the current through the FETs is the impedance of the transformer. A 5 A rating does not mean that the current through the winding is limited to 5 A. You do not say how hot the FETs are getting. Can you post a scope shot of a FET drain voltage? ak
  20. AnalogKid

    Wien bridge oscillator help...

    For my library collection. I've seen many calculator sites come and go, so I like to have two or three links for each type. ak
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