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  1. AnalogKid

    need help with voltage

    It's either a fixed frequency at 60 Hz or a variable frequency from 1 kHz to 100 kHz. Not both. Gotta ask, why do you need a 100 kHz half-wave rectified sine wave at 60 W? ak
  2. AnalogKid

    need help with voltage

    Your question is not clear at all. Are you talking about converting a +5 V power supply output to a +12 V power source? Or amplifying a +5 V signal to a +12 V signal with a 1 A output current capability? In either case, what is the wave shape, and what are the minimum and maximum fundamental...
  3. AnalogKid

    74HC oscillator, how fast?

    There are two factors, rise/fall times and propagation delay. CMOS is basically a current source output, so the output risetime is dependent on the load capacitance. HC has an asymmetrical output current capability, so that affects the max freq. At low frequencies the output is a trapezoid...
  4. AnalogKid

    Can someone help me with explaining a part of this circuit?

    There are two push to make switches with two different reference designators. ak
  5. AnalogKid

    Electronics 101

    You've set some pretty ambitious goals for yourself. Not to be discouraging, but some of your examples will take years to master. Fortunately, there are tens of thousands of electronics tutorial pages and websites; you just fish around until you find one at your level, then fish again for the...
  6. AnalogKid

    Can I get a relay that reverses polarity for the load when not powered

    I've used a bunch of T-90's over the years. They are based on a relay developed by Bosch for automotive applications. Solid performer. ak
  7. AnalogKid

    Can I get a relay that reverses polarity for the load when not powered

    A DPDT relay can be wired to provide one DC polarity when the coil is off and the other polarity when the coil is powered, but power of one polarity or the other is connected to the device at all times. If you want a third state where the device has no DC applied, that is a two-relay solution...
  8. AnalogKid

    Low cycle Pulse generator ?

    IIRC, I think the difference is 200 mA vs. 300 mA, but I'd add a driver transistor no matter what. No matter how tough the part is, IC output stages and automotive power quality do not mix well. Is the relay tied to +12 V, and you are switching the ground side, or is it grounded and you have...
  9. AnalogKid

    Need help IDing parts

    Good answer! Learn something new every day. I wonder if the relative worked for Collins, et al. ak
  10. AnalogKid

    Need help IDing parts

    Yes, crystals, an electronic component that sets the frequency of an oscillator. 3.58 is a common abbreviation of 3.579545. This is the frequency of the color component of a "composite" TV signal. It is a very common part, around $1 brand new. Because of its massive use (one in every TV in...
  11. AnalogKid

    Low cycle Pulse generator ?

    When the ignition key is turned to the start position, cranking starts and the pulse circuit immediately makes an output for one second. yes/no If the ignition key is released before the 1 second is up, the output pulse ends immediately. yes/no If the ignition key is held on for a long time...
  12. AnalogKid

    Modifying AGC circuit

    C3-P1 is a time constant of 0.1 s and a corner freq of 1.6 Hz. On a positive peak, C3 will charge through the Q1 base-emitter junction. When the circuit turns down the signal and subsequent positive peaks are not greater than the voltage across C3, it will discharge through P1 until it starts...
  13. AnalogKid

    Epicure Products

    This is directed at AudioGuru, but anyone can chime in. Since you're as old as I am, you probably remember Epicure Products. What do (did) you think of the EPI-50 and EPI-100? Thanks. ak
  14. AnalogKid

    Water detector with NE555

    It also sinks low approx 50% of the time when the 555 is oscillating, as in post #3. ak
  15. AnalogKid

    Electric Guitar Amp Circuit Check

    AG - I was working on an explanation of how the input impedance of a preamp affects not only the signal level but also the frequency response of the pickup. LOVE the freq chart. ak
  16. AnalogKid

    Electric Guitar Amp Circuit Check

    No, you're not. a) An electrical pickup device for a guitar was patented in the 1930's. That's older than you. The innergoogle is awash in circuits, projects, kits, patents, tutorials, how-to videos, and theory lectures covering every possible aspect of this field of devices. b) And yet here...
  17. AnalogKid

    Electric Guitar Amp Circuit Check

    I agree with Harold. ak
  18. AnalogKid

    Electric Guitar Amp Circuit Check

    Add something more to it.
  19. AnalogKid

    Electric Guitar Amp Circuit Check

    It is *very* difficult to say from your schematic, but almost certainly not. A single transistor does not have enough gain to bring a guitar pickup all the way up to speaker level. Please supply more information about the transistor (part number - ?????), speaker (size, impedance), and a...
  20. AnalogKid

    Voltage Follower Doesn't Work

    All mine, made it up on the spot, straight from Buckeye country. ak
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