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  1. audioguru2

    Does the Magnet with a Staurated Core get stronger if we Increase Current?

    Hi Shahriar, I think that when a magnetic core is saturated then it won't make more magnetism if its coil is fed more current. The extra current is wasted as heat.
  2. audioguru2

    Data Transmission using Xmitters

    A telephone line has a bandwidth of only 3kHz if you are lucky. A good FM transmitter and a stereo FM tuner has a bandwidth up to 53KHz, 17.7 times more bandwidth. It calculates to a data rate of nearly 1Mb/sec. Try it.
  3. audioguru2

    Electronic Stethoscope 2

    7V for a 9V battery and with the low current of this project is a battery that is wearing out. When it reaches 6V then it is dead. Did you connect everything together with the "ground" symbol on the schematic? Did you connect everything together with the "+9V" symbol on the schematic? Did you...
  4. audioguru2

    12 V DC to a 220V AC Inverter AMplfier Design

    Hi Morro, The transformer is fed with AC from the Mosfets.. One side of the center-tapped low voltage winding has 12VDC applied to it from the Mosfets on that side, then that side turns off and the other side turns on, for a square-wave inverter. The DC current in the winding alternates from...
  5. audioguru2

    RC Car

    Permanent magnet DC electric motors on RC toys usually have two 0.1uF ceramic disc capacitors connected from each wire to the metal case. The capacitors arrest sparks from the motor's brushes. The sparks would cause radio interference so the RC doesn't work.
  6. audioguru2

    Electronic Stethoscope 2

    Maybe your batteries are old with a high internal resistance which causes the supply voltages to jump around. Try new 9V alkaline batteries. Does the blinking stop when the volume control is turned down? You are not supposed to touch the mic because it responds to very low frequencies and it is...
  7. audioguru2

    RC Car

    There are a lot of things to consider to make an electric car faster. They are not so simple: Using a battery with a higher voltage will push the existing motor to be more powerful. But the higher voltage will burn out the motor, its electronic drive circuit and the rasdio receiver. The higher...
  8. audioguru2

    Electronic Stethoscope 2

    You never connect a speaker directly to pin 5 of the LM386 because it has a DC voltage. A speaker or headphones must connect to the output of C6 which is the output DC blocking capacitor. The jack for the headphones is where to connect a speaker. Two batteries and a switch that has 2 poles. I...
  9. audioguru2

    SCR Question

    Hi Sundin, Think about how much voltage will be across the resistor. It is less than 34V. That voltage divided by the spec'd holding current determines the minimum value of the resistor. What about the tolerance of the resistor?
  10. audioguru2

    RC Car

    Hi Ilja, Sure we know how to make your electric car go faster: 1) Replace its motor with a more powerful one. It will probably use a higher battery voltage which will burn out the existing motor. The new motor will be bigger and won't fit. 2) Replace the battery with a higher voltage one. The...
  11. audioguru2

    Car audio question

    Car subwoofers can be used at home with a stereo system. They are connected the same as in a car: 1) They need their own high power amplifier and an active crossover circuit to feed their amplifier only the very low frequencies. 2) The active crossover circuit will also have a highpass filter...
  12. audioguru2

    Electronic Stethoscope 2

    Plug an 8 ohm speaker into the jack for the headphones. The LM386 power amplifier IC will provide the speaker with 450mW max and probably cause acoustical feedback howling because the microphone will probably hear the speaker. For a few seconds while C7 and C8 slowly discharge. Then your switch...
  13. audioguru2

    12 V DC to a 220V AC Inverter AMplfier Design

    I showed it a few days ago. Here it is again clearer. What is a drain source? A Mosfet has a drain pin and a source pin. On these N-channel Mosfets, the sources are connected to ground and the drains are connected to the ends of the transformer winding. The center-tap is connected to +12V. Here...
  14. audioguru2

    Low-pass Filter?

    A stepdown transformer and a bridge rectifier makes pulsing DC that won't power an electronic circuit. A huge filter capacitor (20,000uF or more) must be used to smooth it into usable DC. The center-tap of the transformer in the inverter circuit, pin 8 of the LM358 dual opamp and pin 14 of the...
  15. audioguru2

    about infrared remote control

    Hi. Is this our project that you built?: http://www.electronics-lab.com/projects/motor_light/030/index.html Its receiver is missing a very important resistor which provides a DC reference voltage of 0V for the opamp's input.
  16. audioguru2

    Low-pass Filter?

    The schematic for the project has a on-off switch between the fuse from the battery and the circuit. Don't use a switch if you want the circuit to be powered all the time.
  17. audioguru2

    12 V DC to a 220V AC Inverter AMplfier Design

    Hi Sonny, You make everything very confusing when you use Kachew's account. You should register on this site as yourself. Then login as yourself each time. You attached a DOC file instead of a GIF or PNG file for your schematics, and you compressed it as a RAR. Just attach the schematics as a...
  18. audioguru2

    PSU Design for car audio amplifiers using UC2577-ADJ

    The OPA548 is a power opamp. If it has a +60V and 0V supply then its output will be from +2V to +58V, it won't be negative. Even if it is connected as an inverting opamp with a gain of one, then with a +2V input its output will be +58V and with a +58V input its output will be +2V. An opamp...
  19. audioguru2

    Low-pass Filter?

    12VAC when rectified with a bridge rectifier makes a peak voltage of 15V and needs a huge capacitor to filter it into 15VDC. It is fairly high for the circiuit but is safe for the parts. The triangles on the schematic are connections to the negative terminal of the power supply (battery). The...
  20. audioguru2

    mixos turns 24 today!

    Happy Birthday, Mike. Thanks for this great website. ;D
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