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  1. K

    LCR circuits

    I use vectors any way I can. Formulas are easy to work with but, in the case of electronics, they don't make much sense. We need a way to make sense of the relationship without turning it into a sequence of mathematical operations. Do you understand what I mean?
  2. K

    Capacitor charging

    You will notice that even a triangle wave is based on the charging curve.
  3. K

    Digital Phase Shifter

    The only way I know of to shift phase is to switch in a resistor in an RC circuit. You have to change the phase of the oscillator first, then turn it into a clock. Switch in the resistor with a MOSFET. In other words, the resistor goes to the drain and the source goes to the power supply. When...
  4. K

    hv polarity indicator/ voltage optimizer

    Analyzing a logic circuit, the multiple emitter and totem pole, I am left with the idea of circuits that have already been designed. It would be nice to design my own high voltage circuits, though I know they would be crude. High voltage often incorporates the use of other scientific components...
  5. K

    ttl or gate

    A phase splitter is what allows you to get high gain from the totem pole ouput. The totem pole is two NPNs. It is interesting that one NPN is setup for amplification while the other is setup as a voltage follower. I think this is because the phase splitter produces enough gain for the voltage...
  6. K

    Capacitors and energy

    Capacitors store energy w=1/2 CV^2. We take joules per s and multiply by s to give joules. We multiply because the functions are constant and integration is made simple. Joules per s is power and power is a function of current and voltage. So the capacitor can be said to store current. So what...
  7. K

    Capacitor charging

    When using a small value capacitor, a nonlinear situation exists. The signal quickly charges the capacitor. This creates DC charging for each value of the signal and makes it follow the capacitor charging function. Does anybody follow? Ideally, you want all of the signal without the nonlinear...
  8. K

    Analog/Digital GND

    The ground plane can be filled with everything. I think this is due to layout. But I would bet that since ground is a common point, every signal is going to get a piece of it.
  9. K

    transistor uses

    I don't like using transistors as diodes. It seems tricky enough to get a current multiplier to work. Does anybody really accept the simple model of the transistor?
  10. K

    70 volt regulator

    That's the circuit. What does the zener help in that position? Why not use a resistor? Does the zener present a higher impedance to the signal? Also, I am unable to measure the diode of the device, it's just low resistance all the way around.
  11. K

    transistor uses

    The transistor can be used for many things, yet it operates one way. It can be operated as a linear amplifier. It can be operated at cutoff and saturation. It can be used as a resistance, two diodes, or a voltage converter. It may act as a constant current sink or source. Which funtion do you...
  12. K

    OPAMP questions

    The input capacitor is to ground. It is not in series like a differentiator. Do you understand the concept of the emitter element? This is sometimes the resistor R1. R2 is the feedback resistor. The fact that it is an emitter element is why it sets the gain.
  13. K

    How do I make a dc circuit auto-off after 60 minutes

    According to the schematic posted, the capacitor will not maintain the current necessary to keep the transistor conducting. The current is C dvdt. The the dvdt is 0, so the voltage will go to 11.3 and stay at 11.3. It will not discharge like it would with a resistor because the PN requires...
  14. K

    em field detector

    It might be easier to monitor the voltage of the inductor and speculate about the field. But I can see your point. Maybe you could couple the electromagenetic energy to a coil, and amplify the very weak signal.
  15. K

    hv polarity indicator/ voltage optimizer

    What circuit do you use to indicate the high voltage? The circuit must have a threshhold so that you can indicate at least the minimum voltage you are getting. I might use a device that requires high voltage to operate. Have you heard of those pressurized things that shunt high voltage. I can't...
  16. K

    Experimental high voltage bridge rectifier

    It seems it would be difficult to modulate high voltage. Does the TV modulate high voltage or just utilize high voltage? You really could not use a transistor with high voltage, am I wrong.
  17. K

    OPAMP questions

    I have it. The input capacitor causes the gain to increase by 20db per decade. This is because the capacitor produces a 20db per decade roll-off and it is placed as an emitter element. As the frequency is increased, the gain is higher because it is an emitter element. A higher gain means it is...
  18. K

    Transformerless power supply

    A series capacitor is a good idea, but it will require a large one if the filter capacitor is large. This would lead to a pack of capacitors with the rated voltage. This is because a low value series capacitor will drop most of the DC and a large value filter capacitor will not give you much DC.
  19. K

    A/D Converters and Shift registers

    I will have to reword my last comment. I got the thing backwards. The A/D will be a parallel ouput device and you don't need a multiplexar or demultiplexar, whichever is the case. I see the problem you are having with configuring the A/D. Try to find a simple one.
  20. K

    12 volts led power input indicator circuit

    Let's talk specifics. The 120vac will indicate the LED as well as other voltages. We should try to indicate only that which is there.
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