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  1. audioguru2

    Use of LM324 in audio circuit

    The old, old, old LM324 quad and LM358 dual are the first low power opamps ever made. They made them low power by making the output transistors operate in class-B intead of class-AB so they have crossover distortion unless they drive a DC-biased load. They also made them low power by reducing...
  2. audioguru2

    amplify..

    A circuit to boost a DC voltage is complicated. What is causing the voltage drop in your circuit? If you use a transistor to turn a relay on and off then its voltage drop will be only about 0.2V.
  3. audioguru2

    Power dissipation limiter

    I see, good idea. ;D The SCR will gate the pulses from the bridge rectifier. The frequency doesn't matter as long as it reduces the power dissipation. I use Microsoft Paint program to sketch schematics or to copy and paste whole schematics, pieces from schematics or symbols from other schematics...
  4. audioguru2

    tv tuner box with coax to component?

    They have some bugs running on a treadmill that turns a generator, don't they?? ;D ;D
  5. audioguru2

    Heatsink Surface Area

    You need to know a lot more than just its surface area. Which metal? How smooth? How thick? Convection or radiation? That's why real heatsinks are selected from a list of their thermal resistance.
  6. audioguru2

    Power dissipation limiter

    How is an SCR going to reduce the voltage or current? By shorting the unregulated supply? I have seen power supply circuits that automatically switch taps on the transformer to lower voltages when the output voltage is reduced.
  7. audioguru2

    0-30 Vdc Stabilized Power Supply

    U1 doesn't have a negative supply so its output can go only positive. R5 and R6 provide positive feedback so that the output voltage is double the voltage at pin 2. The output voltage begins a little positive and the positive feedback increases it until the zener diode conducts at 5.6V, making...
  8. audioguru2

    0-30 Vdc Stabilized Power Supply

    52VDC is much too high for many parts of the circuit. This I think is too much for the OPA445s, in fact I know it is because 2 of them blew up after I connected it The OPA445 has an absolute max supply voltage of 100V. The factory tests them at 80V. Your circuit gave them a total supply of only...
  9. audioguru2

    Power dissipation limiter

    Your circuit doesn't have a voltage reference. Then the base-emitter voltage of Q1 is a thermometer and Q2 and Q4 boost its current! I don't think the output voltage is regulated so it changes with temperature, input voltage changes and output current changes. You could look at a datasheet for...
  10. audioguru2

    need help for cfl lighting

    700mA from a 6V battery is only 4.2W. The inverter is about 80% efficient so the 9W bulb gets only 3.36W. That would be quite dim. Is that what you want?
  11. audioguru2

    SPUD Gun Timing circuit

    Some guys on another forum are shooting pumpkins 1 mile. It is so far that they asked for a tracking device for them.
  12. audioguru2

    Op-Amp Question

    80dB is a voltage gain of 10,000. 74dB is a voltage gain of 5000. So 76dB is a voltage gain of about 6000. So the common gain is 13.5.
  13. audioguru2

    Datasheet Archives

    www.datasheetarchive.com has a datasheet for a KA2163 as Samsung's IC for a color TV. It was probably made in a lane in Korea called, "SEC 719B".
  14. audioguru2

    Comment about this design...

    Hi Ante, Gary made one or two. The datasheet has a max rating for the IC's idle current which is 10mA for the LM317 in a large case and only 5mA for the more expensive LM117. The reference voltage of 1.25V flows through the resistor which is only 5.2mA for a 240 ohm resistor. Since the max idle...
  15. audioguru2

    Comment about this design...

    The resistor from the output to the ADJ terminal of the voltage regulating IC is 240 ohms when it should be 120 ohms so the output voltage doesn't rise without a load, as per the datasheet. Then the value of the voltage adjustment pot should also be reduced to half also.
  16. audioguru2

    12 V DC to a 220V AC Inverter AMplfier Design

    Yes, that is how they make an AC current in the transformer.
  17. audioguru2

    tv tuner box with coax to component?

    The store where you bought your projector should have a TV tuner for your part of the world. Regular old TV or new high definition? Regular old analog modulation or new digital?
  18. audioguru2

    Power dissipation limiter

    You can change the circuit to "foldback current limiting". When an overload tries to draw more than max current then the circuit reduces the current. For a shorted output the current can be very low. At any current below its max setting, the circuit performs normally. Look in Google for Foldback...
  19. audioguru2

    need help for cfl lighting

    9W for the light tube and maybe as much as 1.8W for the voltage stepup circuit is a total power of 10.8W. Therefore the current from a 6V battery is 10.8W/6V= 1.8A. Do you have a huge battery to supply a current so high?
  20. audioguru2

    12 V DC to a 220V AC Inverter AMplfier Design

    6 Mosfets are not in parallel, 3 are in parallel on each side. There is a very high current in the mosfets. Paralleling them allows them to share the current so each one gets 1/3rd of the total. Paralleled Mosfets share the heat so each one gets nearly only 1/3rd of the dissipation. You could...
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