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  1. K

    120 VAC

    The AC delivered to your house is apparently very sinusoidal. This is a claim I have read. So why a sine wave. Why not a triangle. It is because the sine wave has a low rate of change as it approaches the peak of the cycle. Sometimes the AC is low enough frequency dependent on your circuit, this...
  2. K

    Light bulb dimmer

    What is the construction of a light bulb dimmer?
  3. K

    RC time constant

    Perhaps the most overlooked by most enthusiasts is the RC time constant. The best way to determine if your circuit is good is to compare the time of the RC with the time of the signal. If the time of the signal is short, such a ramp of a square wave, the RC time looks very long to it. If the...
  4. K

    bidirectional re

    I want someone to verify the bidirectional re of a transistor. I could not find the data in my book so I was left to guess. I wondered why you could not have a larger signal on the base when in fact the signal originates at the emitter. It could happen right. Not likely in this situation. The...
  5. K

    complimentary symmetry amplifier

    Often misinterpreted as a pushpull, this amplifier gives the highest voltage gain possible whereas a pushpull is just a current amplifier with a voltage gain of one. http://www.radioelectronicschool.com/reading/reading26.pdf I believe this is the basis for opamp gain. There is also a pushpull...
  6. K

    Speaking about bonding

    Remember in chemistry class where they talked about how certain compounds will bond with other compounds depending on the number of valence electrons in the compund. Those were the good old days. For now I would like to talk about silicon and it's doping. I am talking about transistors...
  7. K

    small current amplifiers

    I have this idea about the operation of opamps. We all know the input transistors are low current. But how accurate are they. We all want to believe that they are perfect. But I think the  manufacturing process for these devices may not be as good as the higher current ones. Specifically their...
  8. K

    PWM

    I am trying to develop the simplest Pulse Width Modulator. It seems you can use an AND gate with the amplifed signal at the input and a reference clock on the other input. Can somebody back me up on the logic here. It seems the only problem is that the frequency can't be too far from the...
  9. K

    Coupling capacitors

    I believe that a coupling capacitor is directly affected by DC. I am talking about low value capacitors that see the signal as discreet DC values because the signal rate of change is low. I can prove this theoretically. Whenever the signal goes DC, the other side of the capacitor will go to it's...
  10. K

    25 Khz oscillator

    Here is something I dredged up in the way of sine wave oscillators. It incorporates a low pass and high pass filter and amplifies noise into a single rate of change.
  11. K

    opamp biasing class A

    Here is the link that describes the output bias current of an opamp. You will see many circuits that do not have a DC bias current. http://tangentsoft.net/audio/opamp-bias.html
  12. K

    60 Hz sine wave oscillator.

    Hello. This is my 60 hz sinewave oscillator.
  13. K

    Resonance

    What is the thory behind resonance. What is it about the capacitor and inductor that lends itself to the open and short at the resonant frequency? I know that in series, you subtract the reactances. I know in parallel they call it a tank. I am assuming in the tank, there is no current from the...
  14. K

    True RMS

    My meter does not measure true RMS. Consequentally I measure a clock signal of 5 volts and get the same 2.5 average and 2.5 RMS. By my RMS calculation, I should get 3.5 RMS.
  15. K

    Negative charge pump

    Here is something a drew up for those interested in a negative voltage supply made with a charge pump.
  16. K

    The simplest audio amplifier

    A guy in the chat room wanted to auto stereo amplifier. I suggested he use a 3A transistor but needs the negative supply. I noticed the 555 timer can be configured to give the -12 volts output. But of course the current is too low. Could somebody post the simple solution.
  17. K

    SAW filters

    I have heard that SAW filters have good attenuation. Has anybody ever used them? I would think their charactersitic is very useful. Could somebody post a circuit with them. I am just curious. I see now that they have funny response to them. Maybe this is the reason for their lack popularity.
  18. K

    Why 50 50 50 maximum power

    The term nonresonant applies to the condition where the reactance is cancelled out and the line impedance is equal to the source impedance is equal to the load impedance and describes maximum power transfer. The maximum power transfer is difficult to see because you might think that a high...
  19. K

    Energy bands

    Doesn't it seem odd that the current in p type is within the covalent band while the n type current is in the conduction band. I would suspect a property difference in there somewhere. Copper has overlapping energy bands whereas it takes the same amount of energy to push an electron in the...
  20. K

    non logic level multiplexar

    What if I want a multiplexar that feeds through the input voltage. This way I could monitor a bunch of voltages by selecting one line and this goes to an A/D. In other words I want to use one A/D and monitor the voltages of many inputs. Does there exist a voltage follwer multiplexar?
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