Search results

Search Forums New Posts
  1. K

    How to generate negative voltage from PIC

    The easiest way to generate -50V is from a battery. The PIC output can switch a MOSFET that is in series with the battery and the load. The positive terminal of the battery is connected to ground and the negative terminal is connected to the load.
  2. K

    Switching power supplies and Earth

    You can't re-engineer an electronics product to be safer in most circumstances. Old pieces of equipment get worn and can become more of a danger.
  3. K

    frequency meter

    You can guess as to an approximate frequency range using other measurement devices. But an oscilloscope or other frequency measuring device is required at higher frequencies and lower amplitudes.
  4. K

    High Voltage low amperage

    A transformer will deliver a high enough voltage that you want. High voltage transformers are expensive, but can usually be found in electronics products no longer used, and be cascaded for high voltgage. Be aware that high voltage burns and shock can occur, and a high enough voltage can lay you...
  5. K

    H-bridge using only n-channel mosfets

    Two N channel MOSFET's can replace the two IGBT's in your circuit. An H bridge is used to produce a polarity change across a load. If your circuit is an H bridge, then the load is what makes it an H bridge. It looks like the voltage at the output is fixed by the zener diode, from your schematic.
  6. K

    Active load circuit 5-8A

    You might want to test the power supply different ways. A variable high power resistor can be used test the supply under DC conditions. Then a circuit can be made to test at increasing frequency loads. Some common electronics products you generally buy can also be used to test the power supply.
  7. K

    LM338 Power Suply Current Regulator

    Hero99, are you a moderator?
  8. K

    Resistors

    I must be wrong. But the high power resistors I bought do not have the value I thought  they had. Why must high power resistors have a value that are not what they say they are. I pay a lot for these high these things.
  9. K

    Analog oscillators

    Are simply constructed oscillators worse than oscillators used today? If they are, can it proved that the oscillators used today are without a doubt, and with no exception better in every aspect?
  10. K

    Linear response

    An opamp can use a thyristor in it's feedback to limit gain. If the error correcting device is at a high enough frequency to detect an unwanted change in the input signal, the gain can be limited. If your going to use high speed logic devices in a circuit anyways, why not utilize them more?
  11. K

    Linear response

    I don't believe linear control is unreliable. But a signal that is produced by logic control can poroduce a more time sensitive response. Microprocessors generate at the the nanosecond. So as far as audio goes, it's much more of a higher frequency than that. Maybe a high frequency expert can...
  12. K

    Linear response

    Most designs employ a large number of components and they generate a lot of noise. But error correction is linear in most cases. If a circuit is going to incorporate a microprocessor, why are smaller circuits limited to simple, linear error correction? A voltage regulator IC, a phase lock loop...
  13. K

    Energy conversion.

    The energy that can be produced from energy sources can be small. Photoelectric cells are being used to produce small amounts of energy, but they produce enough power to power low power devices.
  14. K

    questions about FM Superhetrodyne Receiver

    I think your right, but there are two problems. The incoming signal, let's say centered at 100MHz will not exactly match the oscillator. So the resulting frequency won't be 0Hz. The bandwidth of the incoming signal will result in frequencies maybe to 1MHz. So you could lose something, maybe not...
  15. K

    More PWM questions

    An 80A pulse width modulator is too high of amperage for any that I've seen. I'm sure your refering to high voltage and a low impedance. But either way it's going to be a larger circuit. Logic devices and reactive components are used to produce the initial PWM signal
  16. K

    max232 external capacitors

    The capacitors have to be able to deliver the required voltage to the load, which requires a capacitance that will charge to the voltage within the charge time and maintain the voltage until the next charging time.
  17. K

    questions about FM Superhetrodyne Receiver

    Higher or lower? The oscillator should match the incoming frequency as close as possible. Otherwise, your introducing a different frequency, which results in something more indicernable. Fortunately, most broadcasts have plenty of power and a wide enough bandwidth for audio and video.
  18. K

    Filters

    I was refering more to passive component circuits involving crystals, ceramic filters, SAW filters and other technologies. And, aren't the passive components available today more capable of producing the desired filter response?
  19. K

    Filters

    Hero99, there are a variety of filters available. Many designs use only LC filtering, but is it because other types of filters do not have the requirements to meet the design? Many filters have great response, but a narrow specification and might be intended for only a few applications.
  20. K

    Capacitor Voltage

    The voltage rating of a capacitor is proportionate to the value. The construction of high value capacitors results in more tolerance than lower value capacitors.
Top