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  1. audioguru2

    Dual op amp IC that works at 2.4V

    Hi Xtp, Opamps don't supply much current. There are some tiny surface-mount power amp ICs for earphones that operate from a low voltage and use a voltage doubler circuit for their power supply. They are nearly impossible to solder. You could use an MC34119 8-pin ordinary-size IC that has two...
  2. audioguru2

    Gas turbine bike.

    Someone on an electronics forum built a jet tubine from a turbo. He fueled it with diesel and started it with propane. He was asking for a PWM circuit to control its fuel pump. He said it didn't have a big flame coming out like I thought it would. I think he used it on his go-kart. I saw a...
  3. audioguru2

    plants watering watcher 1

    Hi Mike, Just add another CD4093 IC. Connect its 1st gate's inputs in parallel with the inputs of IC1b or IC1c. Its output drives all 4 inputs of gates 2 and 3. Their outputs are connected together and to the anode of the green LED. The cathode of the LED is grounded and also the inputs of gate...
  4. audioguru2

    Digital Remote Thermometer

    The project tells all the details about how to make L1.
  5. audioguru2

    design analysis on 3kva automatic voltage regulator

    3000V @1A? 3000A @1V? Something in between? AC or DC? We can't assist you unless we know exactly what you need.
  6. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    The bags were for BS, weren't they? ;D
  7. audioguru2

    Help for power supply.

    Hi Moutoulos, That circuit would make a lot of smoke if you tried a 2V load at 20A. Each output transistor would try to dissipate 190W and would melt. If you want current adjustment and regulation for it then you must add an adjustable current regulator circuit to it.
  8. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    Who copied whom? Which came 1st, the Philips one (or was it ST?), or Texas Instruments' TL494? ??? ??? National, Motorola and Fairchild also had their own. They're all about the same.
  9. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    Hi Nura, Maybe great minds think the alike. When I was young, I designed an audio amp using my own idea of a "complementary darlington" pair for each output transistor. I built it and it worked much better than other amps of that time. A few months later, my circuit was shown by somebody else in...
  10. audioguru2

    led lamp

    Electrolytic capacitors with 10V, 16V, 25V, 35V or 50V ratings are fine. Go to www.farnell.com and click on your country's flag. They have their part number 408554 for ICL7660CPA made by INTERSIL for AU$2.55 each and they are in stock today. They deliver by Parcel Post or by courier if their...
  11. audioguru2

    Choice of small signal BJTs

    I can buy only one 2N3904 for $.08CAN at Newarkinone and they cost less if I buy more. I know it, I like it and I use it. I wouldn't touch a cheap Chinese 2SCxxxx from a radio. :P
  12. audioguru2

    Equalizer ...

    It might be alternator whine. Connect a 1000uF/35V capacitor with very short leads to where the +14.4V and 0V are connected on the amplifier's circuit board. The stereo cable from the output of the CD player to the amplifier's inputs should be shielded audio cable, not an extension cord for...
  13. audioguru2

    +/-15V power supply using LM317 and LM337 regulator ICs

    Then since the supply range of the IC is very wide, you don't need the pots, just 2.7k resistors instead for +-15.3V.
  14. audioguru2

    I need to balance an amp HELP!!

  15. audioguru2

    2N3055 Power Amplifier

    Hi Hti, With a 60V supply, this amp can deliver about 45W to an 8 ohm speaker or about 80W to a 4 ohm speaker at clipping. Cascaded transistors are connected in series, which won't accomplish anything. If you add additional 2N3055 transistors in parallel with the existing ones, using emitter...
  16. audioguru2

    basics of electrical supply

    I won't try it but I think a person's capacitance to ground passes enough current from a live mains wire to be felt as a mild shock. It is enough current to light an NE2 neon bulb in your hand. We use the extremely high mains frequency of 60Hz over here! Long ago, the mains frequency was only...
  17. audioguru2

    LED driving

    Hi Prateek, LEDs are getting better and cost less. All traffic lights in my pretty big city are LEDs. They are going to convert the bus shelters to solar-powered LED lighting. My city gave away LED Christmas tree lights and they save a huge expense in power. I can't use my laser pointer as a...
  18. audioguru2

    MICRO ANTENNAS

    Hi Prateek, I don't see any advantage to change broadcasts to microwave frequencies now. I think I said that before.
  19. audioguru2

    Choice of small signal BJTs

    Yes, and BC557 for PNP. The BC549 NPN and BC559 PNP are especially low-noise types.
  20. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    Nura, It looks like Sasi perfected the original inverter circuit. It had a common-emitter transistor in the output of the IC driving another common-emitter transistor driving a complementary pair of emitter-followers, while Sasi replaced them all with simply an emitter-follower and used the...
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