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  1. AnalogKid

    Solenoid energized indication

    I thought the asterisks and other language made it clear that a simple series connection probably will not work. Also, For that arrangement there would be no series resistor, as the solenoid coil resistance would limit the LED current to below 50 mA. And as I said, if the coil cannot do that...
  2. AnalogKid

    Solenoid energized indication

    You can put the LED in series with the solenoid *only* if it is a very low power solenoid. In a series circuit, all of the current goes through all of the parts, so whatever current the solenoid draws has to go through the LED. Since most LEDs are rated for under 50 mA of continuous current...
  3. AnalogKid

    2N3055's and heat

    In both link's datasheets, the Absolute Maximum Ratings sections state the input-to-output max differential voltage. Nowhere in that section or in any of the standard parameters tables does it say anything about a max input voltage. National Semiconductor made a big deal about this when the...
  4. AnalogKid

    2N3055's and heat

    Three-terminal voltage regulators that have a floating adjust pin, as opposed to a fixed ground pin, are different in the way they function and the way they are specified. For example, there is no input voltage spec for an LM317. What is specified is the max. input-to-output voltage drop...
  5. AnalogKid

    2N3055's and heat

    To do what? A little clarity would be nice. Thermal runaway, as in what happens in a bipolar transistor audio amplifier without output transistor compensation, cannot happen in a power supply. Surely not. Not ever. Use Ohm's law. Nothing is stated explicitly, so let's assume you are talking...
  6. AnalogKid

    Do timers timer?

    Just the opposite. When you trigger a 555 configured as a monostable multivibrator (the official name for a one-shot timer), the output goes high immediately, and then sits there until the timer "reaches a set point". At that time it goes low again, and waits for the next trigger. ak
  7. AnalogKid

    Brain tester.

    Power, signal discrimination, and LED drive with only two wires? Yes, certainly possible, but not without some electronics at each 3-LED location and corresponding electronics at the driving point. What is the current through each LED? Are the 3 LEDs a) mutually exclusive (only one at a time...
  8. AnalogKid

    cd4067be

    In what way is it not working? What does "frantic" mean? Are you using this part as a multiplexer or demultiplexer? Can you post a link to a datasheet so we have some clue as to what the part does internally? If you have a protoboard, small power supply, voltmeter, and 21 jumpers, you can...
  9. AnalogKid

    cd4067be

    Frantic? Schematic?
  10. AnalogKid

    100V switch

    What are the "poor results"? In what way does the so simple circuit not perform adequately or correctly? ak
  11. AnalogKid

    100V switch

    Your question and schematic are missing critical information. Where on the schematic is the 100 V input? Where on the schematic is the 100 V output? Which signal on the schematic is the one that switches the 100 V on and off? What does "cca. 3v" mean? ak
  12. AnalogKid

    Inverting op amp attenuator help

    Yes they do. LT1007: Look at the power supply rejection ratio voltage range and three of the parameters plots. ak
  13. AnalogKid

    Parrot MKi 9200 remote control Help Please

    1. A nicely formed question set with a schematic - excellent start. 2. I recommend all CMOS logic, lose the 5 V regulator, add some transient protection. 3. Logic chip inputs (TTL, CMOS, whatever) usually do not have internal pull up or pull down elements. CMOS in particular is very...
  14. AnalogKid

    Circuit Board for Human Touch EMS-12 Massage chair

    Need a photo. 94V-0 is the flammability rating of the pc board, not part of the part number. Also, ebay often has working parts and assemblies recovered from otherwise broken devices. ak
  15. AnalogKid

    6 layer pcb stack

    Thicker copper has lower resistance for the same trace width, and can carry more current for the same temperature increase. There are online calculators for this. It is not a linear relationship because thicker copper also has more overetching or etch undercut, which decreases the effective...
  16. AnalogKid

    Gel Cell 12 Volt Bat

    I like PowerSonic batteries. I usually buy them through distribution rather than online (amazon, ebay, etc.)
  17. AnalogKid

    need to make a circuit

    You can do all of this with low cost electronic modules available on ebay. A "cycle timer" can be programmed for the on and off times, and a small "wall wart" type 12 V power supply can power it. http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=cycle+timer+module&_sop=15...
  18. AnalogKid

    Vibrating Metronome Project

    A motor-vibrator is a small motor with an offset weight. Between the mass of the motor armature and the mas of the weight, there are definite speed up and slow down times. At 0.33 s per vibration burst, is there enough time between bursts to make feeling them separately possible? ak
  19. AnalogKid

    Calculating resolution.

    Divide, not multiply. ak
  20. AnalogKid

    MMF

    No. ak
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