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  1. K

    BCD counter

    I was looking for an ordinary counter, but I only found a BCD counter. It turns out that it works the way I wanted it to. I had planned on using a regular counter fed to a decoder. Each sequence would decode one output. This is what this device does. Maybe we should call this a counter/decoder...
  2. K

    inverter oscillator

    I built an inverter oscillator with two inverters connected by a capacitor and a pullup on the first inverter. The output of the second inverter is fed to the input of the first inverter. The problem I'm having is that it will only oscillate when I touch the side of the capacitor, which shortens...
  3. K

    pulse width modulation

    Pulse width modulation involves a capacitor and associated logic. When logic is applied, the capacitor is allowed to charge at one rate. When logic is applied, the capacitor is allowed to discharge at one rate. I suppose you could use a 555 timer, but isn't there an even simpler circuit if...
  4. K

    TTL inverters

    I looked at the schematic for the inverter and am having trouble with it. The input transistor is not biased to work like a transistor and I have seen a representation of two diodes in a book. Why doesn't the schematic show these two diodes instead of the transistor?
  5. K

    Why use RMS

    RMS produces the same power dissipation as it's DC equivalent. 6vrms produces the same power dissipation as 6vdc. The mathematical representation is as follows: square the equation, integrate, then take the square root. There must be zero offset to get the result Vrms = .707Vp. It is the job...
  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

    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...
  9. K

    LCR circuits

    Has anybody seen the calculations for the more complicated LCR circuits. I understand the basic circuits, but any addition is not well illustrated in the book I have. Take a simple series LC and parallel the capacitor with a resistor. This goes beyond what I have seen being calculated. If a...
  10. K

    Impedance matching

    I want an easy way to determine the matching characteristics of a line. I want the output device to be any resistance, the input device to be any resistance, and the cable a 50 ohm. What is the length? How can we determine this without going to any trouble?
  11. K

    70 volt regulator

    I have this power supply that I was given that takes the 120vac and converts it to 50vac. The current of the bridge is 1.5A max. The regulator has a control line, input, and output. The output is fed to the base of a darlington and the collector goes to the control. The emitter has a zener diode...
  12. K

    RJ45 network card to IR

    I am refering to the project found on your home page. What is going on with the batteries? Please explain the relative voltages surrounding the photodetector, which is forward biased. Are the two batteries working together? Project link: http://www.electronics-lab.com/projects/pc/023/index.html
  13. K

    OPAMP questions

    You can see from the evidence, a lot of opamp configurations, that the designers are willing to put anything around an opamp. Every single one of those configurations acts differently on the bias. Does anybody else think that the opamp is being too lenient when it comes to external circuitry.
  14. K

    Amplifier circuits

    Does anybody happen to notice the wide array of amplifier circuits available. I am tempted by the IC selections but am wary of the configuration data. I don't like the idea of a circuit where the external components aren't dictated. I want to know what the components are doing and how this...
  15. K

    series RL

    I let the resistor be a higher value so that Vs is in phase with Vr. This allows me to calculate Vl rather than measure it. Vl is 90 degrees out of phase and it throws off the measurement such that the voltage doesn't add up. Does anybody have experience with this? I think the voltage can be...
  16. K

    regulators

    I am concerned with linear regulators and switching regulators. It occured to me that the switching regulator has a filtered output. I believe that a regulator should regulate and not filter. Does anybody have experience with power supply regulators?
  17. K

    transistor voltages

    I am using a 3amp bipolar transistor. My power supply won't handle the 1.5 A that I need. Does anybody want to guess as to the voltage I should use to bias this.
  18. K

    Capacitor variety

    Does anybody notice the variety of capacitor types that exist. I am sure there is a measurable difference, but it is subtle. Of course the value of the capacitors are different, given the same construction. My problem is my meter. It' doesn't measure low voltage AC very well. It's a radio shack...
  19. K

    author of the transformer article

    http://www.electronics-lab.com/articles/transformers/index.html I found your article very interesting and very in depth. I am not interested, at this point, in mass production. My question is about the electrical characteristic. My calculations involve inductive reactance rather than number of...
  20. K

    transistors

    Does anybody notice how often the biasing is less than optimum when trying to incorporate a few transistors in a circuit. I seem to be satisfied when the circuit works on paper, even though I am applying a signal directly to a PN junction. Any thoughts as to why many circuits can get away with this.
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