Search results

Search Forums New Posts
  1. C

    20 Watt LED Dimmer Circuit diagram

    Here is the PCB:
  2. C

    Variable capacitor

    You can make the whole thing with 2 sheets of cooking foil. You really need a couple of stages of amplification to get any sort of volume out of the project. This is all covered in the Crystal Set article. You can even do away with and use a variometer.
  3. C

    Variable capacitor

    "So would they be the 30 pF ones Dorke mentioned above.?" No.They are about 120p or higher. The mylar dielectric gave them the high capacitance. On talkingelectronics.com under Crystal Set I show how to make a variable cap with cooking foil
  4. C

    Filter Choke for power supply

    There is a huge difference between 120Hz and 180kHz and 100mA and 5 amps.
  5. C

    Filter Choke for power supply

    You are much better of to use R instead of L. The only reason they used an inductor: IT WAS FREE !!!!
  6. C

    Thermistor Temperature Sensor

    Set the trigger at 14 degrees Or you may be able to add a resistor in series with the sensor.
  7. C

    Filter Choke for power supply

    "But they *can* be calculated. If you're actually interested in a theoretical analysis, go look up pi filters and play with the math." Why bother working anything out when you can simply "turn on the radio."
  8. C

    Filter Choke for power supply

    "I was wondering how these values were calculated." They weren't calculated. They only had 8 mickey 16 and 24 mickey to deal with. They just put the values in and listened to the hum. The speaker magnet was already set by the speaker manufacturer and you just tried the others.
  9. C

    Filter Choke for power supply

    At 60Hz the choke will be enormous. It is much better to use a resistor and larger capacitors.
  10. C

    Battery on a breadboard

    The output voltage from the battery changes according to the value of the resistor placed across the battery. The INTERNAL RESISTANCE and the resistor across the battery create what is known as a VOLTAGE DIVIDER. 10 ohm and 20 ohm produces 3v across the 10 ohm and 6v across the 20 ohm. 100...
  11. C

    Battery on a breadboard

    Because the battery has a little resistor inside it and it is technically called INTERNAL RESISTANCE. Suppose this resistor is about 20 ohms. When you place a 10ohm resistor across the battery, the real circuit is a 9v supply and a 20 ohm resistor connected in series with a 10 ohm resistor and...
  12. C

    Connecting a powersource directly to a SLA Battery

    12v will not charge a 12v battery.
  13. C

    Theoretical Half-Bridge Inverter Explainantion

    I don't like the term half bridge because it can mean two different circuits. I don't like the term inverter because it can mean two different things.
  14. C

    spearte circuits

    Why do you want to use an opto-coupler?
  15. C

    pwm to analog

    Why do you want to use an opto-coupler?
  16. C

    Energy Lost Due To Friction

    The friction component is so small that it would be impossible for you to calculate. A simpler method is to use a spring scale and measure the force needed to pull the trolley along a flat surface.
  17. C

    Polarity change for linear actuator logic question

    Do you want to use two touch plates?
  18. C

    An unidentified component

    It has 2 wires and is not faulty. Put it back.
  19. C

    Need help with school project; photocell, op amp, and 555 timer

    How you are going to toggle the LED is beyond me.
  20. C

    Need help with school project; photocell, op amp, and 555 timer

    So far you have achieved nothing. It takes no skill what-so-ever to over-design a circuit. You are going to have enormous difficulty interfacing the op amps to the 555. You have painted yourself into a corner that even I cannot extricate you from.
Top