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  1. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi again Emiliano, I am sorry that you also discovered ripple with this project. Many members have the same problem because the transformer is "only" 24VAC and needs to be 30VAC in order for this project to produce regulated 30VDC at full load. As Ante suggests, try using 10,000uF or more for C1...
  2. audioguru2

    Power MOSFETs

    Hi Cuckoo, Thanks for confirming my theory. Good article.
  3. audioguru2

    earth leakage protection

    Search in google for Ground Fault Interrupter.
  4. audioguru2

    Condesor Mic Pin Map?

    Hi Shahrier, Over here, we call that type of microphone "Electret". A condensor microphone needs a high voltage of about 48V. An electret mic has a high voltage charge built-in, and also has a built-in FET that needs a small current at about 5V. Your 2nd diagram is for a stereo mic which headset...
  5. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Dan, If all that you need is up to 15V at up to 3A, then our 30V lab power supply project is too much for you. A simple LM350T 3A, variable-voltage regulator IC will work well. Its voltage adjusting pot can easily be replaced by switched resistors like I showed before. The datasheet is here...
  6. audioguru2

    emp

    Hi Dozens, What is an EMP? Is it just a big SUV, like a Hummer? Motor home? Cameras use geared or stepper motors to turn them. An additional motor is used for lens zoom.
  7. audioguru2

    22 Watt Amplifier

    Hi Christiano, Our simple little FM transmitter project is really just a toy: 1) Its carrier frequency will drift all over the place. Sony's is probably frequency-synthesized using an accurate crystal. 2) It doesn't have audio pre-emphasis, so on an FM radio it will sound something like an AM...
  8. audioguru2

    22 Watt Amplifier

    Hi Cdonke, Of course you have another amplifier for the speakers, it's in your stereo! Like I said before, "You can't connect this new amplifier without disconnecting the existing amplifier", with a switch. When you connect amplifier outputs together, the one that is not being used will say, "My...
  9. audioguru2

    digital voltmeter

    Hi Mahalkoh, Why are you arguing about the circuit design when it and the schematic are in the manufacturer's datasheet? Don't you believe the manufacturer? Are you trying to make it different? The ICL7106 is designed for ranges of 200mV, 2V and 20V, and all ranges start at 0V. Is that acceptable?
  10. audioguru2

    22 Watt Amplifier

    Hi Cdonke, 22W (that's with 10% of awful sounding distortion, it is 15W at clipping) per channel into 4 ohms is what most "ordinary" car radios provide. That is also the same power that a 200W (10% distortion, peak or maximum power, 4 channels total) car system provides. It certainly isn't the...
  11. audioguru2

    Frequency Counter

    Hi Inferno, Why do you want to change the semiconductors? It looks like a very nice project that is designed to use those ones. If you can't get the parts, or don't want to program its microcontroller, then just buy the kit. I'll bet that it eats batteries because of its LED display. At first...
  12. audioguru2

    Question about ttl IC

    Hi Steven, Yes, they seem to call any kind of IC an opamp. Somebody probably told them that an opamp is an IC and that a logic chip is also an IC, so they thought, "Hmmm, they are both the same". ;D I have a catalog that lists hundreds of LEDs and their important spec's like "maximum reverse...
  13. audioguru2

    Question about ttl IC

    Hi Steven, Nope, the 74LS193 is not an opamp. Just check with Google.
  14. audioguru2

    Schematics Variable current 12v 60A to 0A

    Hi Ante, Soon I'll be huntimg for Mosfets and I'll let you know how I decided on one. My catalog has about 1000 Mosfets and the price list is separate from the spec's. Therefore it will be difficult to choose. I will probably make a list of Mosfets that have the spec's that I need, and when I...
  15. audioguru2

    Schematics Variable current 12v 60A to 0A

    Good idea Ante! The 555 will work fine on 5V, and the attenuating resistor for the opamp won't be required. So a 78L05 for both. Dazza's Mosfets are not very powerful, probably better ones can be found. The ICL7667 can drive many Mosfets but is supply line filtering must be increased.
  16. audioguru2

    Schematics Variable current 12v 60A to 0A

    Hi Dazza, Are you going to use an ICL7667 driver from Farnell? Good. It needs only a 0.8V to 2.0V TTL input voltage (but can take much more), and your AD8061 opamp used as a comparator is fully spec'd for a 5V TTL supply. So why not just use a 78L05 5V regulator for the AD8061? The AD8061 works...
  17. audioguru2

    Now im confused! RE RJ45 ir network

    Hi Stuee, Even Google hasn't heard about a 74HS04, except for your post before asking where to get some, and a school project without a date. Maybe that's why the author completely re-designed the circuit in this forum: http://www.electronics-lab.com/projects/pc/023/ and used 74AS parts. Our...
  18. audioguru2

    regulated 12 v dc and 500 mA current o/p

    Hi Kevin, If you have a low peak-to-peak voltage (which is called ripple) at the capacitor, it shows that the capacitor is filtering well, and is large enough in value to supply current to the load without discharging too much before being charged again by the next rectifier conduction. If you...
  19. audioguru2

    regulated 12 v dc and 500 mA current o/p

    Hi Kevin, Of course your rectifiers cause a voltage loss in your power supply circuit. But it has nothing to do with high impedance nor peak-to-peak. The rectifiers conduct a very high current briefly while charging the filter capacitor. The rectifier current is limited only by transformer...
  20. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Newguy, Didn't you learn Ohm's Law? 10V across 80 ohms creates a current of 125mA, not 0.5A. If you want 1A through 80 ohms, then the voltage across it must be 80V! How many volts do you need to create a current of 1A to flow through a resistor with a value of 1M? Steven (Sparky) knows. If...
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