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  1. audioguru2

    0-30 Vdc Stabilized Power Supply

    Exactly the same. R2, R3 and R7 will probably need their wires bent around under them. C1 can be mounted on the chassis with a clamp. No, No! Two 10,000uF/16V caps in parallel equals a 20,000uF/16V cap. If you put them in series their value is halved to only 5000uF and the one with the lowest...
  2. audioguru2

    switching diode

    Hi I'm here where are you..... , where is your search for Diode Switching Applications on Google? I went there and found 77,500 links. ;D
  3. audioguru2

    batteries

    Your link to the battery doesn't work.
  4. audioguru2

    AC motor and power inverter, can it work?, 1hp ac motor, 12v to 120ac 2000w inve

    Hi Ray, Look at Power Factor Correction on Google. Basically a capacitor is added across the mains at the correct time and its value must match the motor's load. It would need different ones switched-in if the motor's load (treadmill's heavy weight user) or speed (treadmill) is changed. ;D
  5. audioguru2

    sound to current or voltage amplifier

    Hi Mark, Welcome to our forum. ;D It is difficult for me to know the output level of your microphone without knowing its type nor sound level to be picked-up. The mic will need a shielded audio cable to connect to an amp. A simple amp is an LM386 which is an IC with only 8 pins. It has a choice...
  6. audioguru2

    AC motor and power inverter, can it work?, 1hp ac motor, 12v to 120ac 2000w inve

    Hi Ray, I think any motor draws a high inductive current when it starts that the meter can't read very well. The inductive part overheats the transistors in the inverter. The inverter just ain't powerful enough! You could add Power Factor Correction to the motor with a changing capacitor but it...
  7. audioguru2

    LM317K regulator current problem

    The LF411 is good, the LM318 is rated for a 40V supply but has diodes across its inputs that might messup the circuit during over-current and the OP07C is ordinary but with an excellent very low input offset voltage not needed here. I was thinking all afternoon about the TI chip I mentioned in...
  8. audioguru2

    0-30 Vdc Stabilized Power Supply

    B and C are fine. They are rated for higher voltages. The current gain of power transistors drops at higher currents and some are weak anyway. Your 4.1A transformer can power this project to produce 3A output if you use two 2N3055 transistors with emitter resistors and a pretty big heatsink. You...
  9. audioguru2

    555 timing circuit

    Nice goin', Blogbo! ;D Yahoo!                                  Yahoo! ;D 
  10. audioguru2

    LM317K regulator current problem

    Hi Smokey, Don't you have 26VAC as an input to the full wave bridge rectifier that I showed? Then C2 will be pumping up and down, charging C3 through D6 at 50 or 60 times per second. Without a load, the zener diode should get warm with the negative current through it and have a voltage across it...
  11. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi SupeR-NovA, Welcome to our forum. ;D Why dual? You won't be able to have one as a negative supply. You won't be able to put them in series. If they have their own transformers and your parts marked in red and are completely separate, then you can do anything with them except not parallel them.
  12. audioguru2

    i don't get it?

    I've soldered surface-mount parts without any problems, but I didn't use the 150W soldering gun like you. My soldering iron is temperature controlled and I have a small tip for it.
  13. audioguru2

    LM317K regulator current problem

    Hi Ante, I just noticed that National's power supply circuit uses their old LM301 opamp with a 41V total supply, but their max for it is only 36V. Shame on them! :( The LM301 works with its inputs at its positive supply, but I don't think that feature is required in this circuit. The TL081...
  14. audioguru2

    i don't get it?

    You used 20 tiny resistors in series instead of a single big one? I think you cooked a few. Measure each one with your ohm-meter to find them. Did you ever get the LEDs to light dimly? Does the fan run?
  15. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    Hi Roderick, That's a wonderful monster you built and it's great that it works so well. ;D Thanks for the tip about more powerful transistors. Where did you get the huge heatsinks and that huge transformer?
  16. audioguru2

    LM317K regulator current problem

    'ow do dey do dat? A charge pump works by charging a capacitor when the transformer terminal swings positive, then discharging the capacitor into the load when the transformer terminal swings negative. I didn't calculate the actual voltages of the circuit which depend on how much the capacitor...
  17. audioguru2

    LM317K regulator current problem

    Then D6 is open or backwards and doesn't conduct.
  18. audioguru2

    NiCd Battery Powered LED Lamp

    Hi Xtp, Getting a higher voltage or current from those DC-DC coverters requires modifying or changing them to get a higher current in their inductor. Look in our Articles section for the good article about DC-DC converters: http://www1.electusdistribution.com.au/images_uploaded/dcdcconv.pdf
  19. audioguru2

    LM317K regulator current problem

    C3 sould have more than 6V.
  20. audioguru2

    LM317K regulator current problem

    Hi Smokey, Each 0.47 ohm resistor will have a max of 2A and will dissipate 1.88W. A 2W resistor will get very hot so use 3W or 5W resistors. Use the simple capacitor-coupled charge pump circuit in our 0V to 30V project for your -6V supply. It uses a zener diode for regulation.
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