Search results

  1. audioguru2

    10kHz FM modulation

    Hi Walid, FM radio stations and TV audio don't use a variable resistor to keep their modulation index controlled. They use a compressor/limiter electronic circuit to control the level of the audio automatically. The max allowed deviation for mono broadcast FM is 75kHz.
  2. audioguru2

    50 ohm antenna

    My little FM transmitter project has a range of more than 2km, with a piece of wire as an antenna #22AWG about 80cm long. I didn't calculate it, I just used a piece of wire that I had. The range would probably be less if the wire was shorter. ;D
  3. audioguru2

    IR photodiode

    Learn the basics of electronics then you will understand technical talk. There isn't an "other world". Sorry, I already answered your question clearly. ::) Hee, hee. ;D ;D When I am designing a complicated electronic circuit, my wifey thinks I am "in another world". ;D ;D I'm just an...
  4. audioguru2

    FBAS to RGB Converter

    Hi Shahriar, What is FBAS? What is the output of the camera? Isn't it composite video with colour and sync? Use the camera's output to AM modulate the carrier of an oscillator set at the frequency of an unused TV channel in your area. Then you can watch it on a TV nearby. You could record it on...
  5. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    Good point, Alun! ;D But not if it had a transformer from a microwave oven that wastes a few hundred Watts because it doesn't have enough turns, therefore its inductance is too low.
  6. audioguru2

    Electronic Stethoscope

    Its gain is high so the wiring of a breadboard would pick-up mains hum. A breadboard would work if you put it in a metal box connected to its ground. ;D
  7. audioguru2

    Design and construction of 3kVA inverter incorporating a 200Ah battery

    Hi Musty, You need to learn Ohm's Law and the Power Law about Volts times Amps before studying circuits like an inverter, an oscillator and using sine waves. Then you will learn about many oscillator types, and calculating their frequency is simple. Then you will learn that amplifying a sine...
  8. audioguru2

    My new project

    Hi Staigen, We went to school such a long time ago that many nations have since changed their name. I was also looking for the new nation called Jamica, but couldn't find it. ;D
  9. audioguru2

    MICRO ANTENNAS

    The antenna on my new cell phone is only 1.5cm on the outside of its case, but might be a little longer inside it. Its max output is 1W at microwave frequencies. There are millions (thousands?) of cell phone base station transmitters in my city but only a single radio station transmitter for...
  10. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    You can't feed 50A from the car battery through the resistance of the wiring and contacts of a breadboard. Look at the size of the wires on booster cables. They can carry 50A.
  11. audioguru2

    LM317 Variable power supply

    He fried his pot because the LM317 was connected backwards. A pot that gives a "burning smell and a buzzing noise" is ruined. :'( His LM317 might also be ruined. :'(
  12. audioguru2

    Internet Problems

    Thanks, but there is another hurricane coming down there, and many more after it.
  13. audioguru2

    Polyester cap?

    I use 1uF polyester caps in other projects. In my LED fader project I used a cheap electrolytic since it is charged and discharged with a single polarity. It would be very difficult to make a fader so the fade time varies randomly.
  14. audioguru2

    Fridge door alarm

    Tilt your fridge backwards slightly. Gravity will close its door if it isn't open too far. Clean out the fridge so stuff inside doesn't block the door. Don't keep your dog nor pet alligator in the fridge. ;D Seriously, if you power the circuit from 6V, you could replace the buzzer with a 5V...
  15. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    Hi Harry, The modified 500W inverter is simply a CD4047 Cmos oscillator/divider/opposing outputs IC driving LM358 dual opamp buffers to increase its output currents. Each buffer drives sets of transistors connected in a darlington arrangement and the output transistors are paralleled for very...
  16. audioguru2

    Polyester cap?

    I made LED fading projects something like this one. I use red, green and blue ultra-brite LEDs, each with their own fading circuit and each circuit has a slightly different rate. When shining on a white ceiling they combine to make all colours of a rainbow with the colours and their brightness...
  17. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    The project of the 500W square wave inverter is here: http://www.electronics-lab.com/projects/power/033/index.html and is updated with a circuit that works. You could make a pure sine wave inverter with a high current linear amplifier driving a transformer and waste a lot of battery power as...
  18. audioguru2

    LM317 Variable power supply

    My old fashioned slide rule says 25mV. You slipped the decimal again. :( Did you solder it to a huge silver plate with liquid nitrogen for cooling? ;D
  19. audioguru2

    0-30 Vdc Stabilized Power Supply

    Doesn't your viewer show PNG? Here they are as GIF:
  20. audioguru2

    0-30 Vdc Stabilized Power Supply

    I think it would be very difficult to set the proper voltage of this supply to the hiccup point in the charging voltage curve of a battery. If you set the voltage slightly too high, the battery will continue over-charging. I forgot to move the supply output connection on my previous post. I've...
Top