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  1. C

    Driving both N and P mosfet with same power supply

    Use an NPN transistor to drive the P-channel MOSFET
  2. C

    Need on a high watt led

    Start by including a one ohm 5 watt wire wound resistor in series with the LED.
  3. C

    Need to short DC motor terminals when not in use

    Don't forget, the motor will creep when shorted.
  4. C

    BJT Basics questions

    For a beginner, you are trying to go into far too much detail. Here is a simple circuit that shows 2 transistors acting as an SCR:
  5. C

    refrigerator causes power surge

    A fridge takes a lot more current than a reading light. You can try a 2 bar radiator.
  6. C

    Help With Kids Homework

    You have answered your own question. There is current flowing in the blue loop and this becomes the primary winding of a transformer between the blue and green windings. The green winding simply increases the voltage. If the blue item were a wire, there would be NO current. What do you think a...
  7. C

    Help With Kids Homework

    I have told you before, that you are entirely WRONG. The first current metes used 10 turns or more of wire on a coil and this coil was placed over the wire to detect the current. But this is very inconvenient when the wire is already connected to the switchboard etc. So, some clever person...
  8. C

    Help With Kids Homework

    The reason why clamp meters use a Hall effect device is this: So they can measure DC. You are confusing the issue with irrelevancies. "Clamp on meters commonly uses a split core" They use a split core so the meter can be wrapped around a wire.
  9. C

    Help With Kids Homework

    The fact that you are missing out on is the clamp-on meter is a SINGLE TURN. This single turn is now used as the primary of a transformer that steps up the voltage to operate detecting components. Many of these meters simply use the magnetic flux produced in a core to activate a HALL DEVICE...
  10. C

    Help With Kids Homework

    What you are saying, in fact, is entirely incorrect. Look at a clamp-on AMMETER. It has to be around the wire to detect the current-flow. You are confusing two different features of INDUCTION. Yes, two parallel wires can be used to show that the second wire picks up the field from the first...
  11. C

    Help With Kids Homework

    You really have to convert the symbols to real components and then thread the loop into the circuit so that it hangs on the wire making the connection between the switch and the resistor. Current will only really flow in the loop when the wire is inside the loop.
  12. C

    Single Digit Seven Segment Display Scoreboard HELP!!

    A have a 2 digit 7-segment display scoreboard. The circuitry is much more complex than you think. You can only put three white LEDs in series
  13. C

    Battery Powered Vacuum repair

    You will find one of the cells is faulty. Charge them all and get a globe (3v to 6v) and try each cell. You will find one does not light the globe.
  14. C

    Transistor radio speaker

    "If the set has an output transformer, it possibly had a 4Ω speaker " NOT TRUE. Nearly all 99.9% speaker transformers were 800:8 I have never heard of xxx:4 output transformers. It could be 32 or 50 ohm with 32 ohm being most likely for an old radio if it is class A. "Speaker impedance...
  15. C

    led lamp assembly help

    How can you regulate the current when you have absolutely no idea of the characteristic voltage of the LED at the current-level? The resistor KNOWS. It has built-in intelligence and knows exactly what current to deliver at a range of supply voltages. Don't get the resistor too hot or it will...
  16. C

    Change LM2575 minimum input voltage to 8 volt

    There is no LM2575-7. Use any -3.3 -5 or adjustable version and use the adjustable circuit to jack up the voltage to 8v. Or use a commonly available 7805 or LM 317 regulator in "jack-up" circuit.
  17. C

    1 2 c loop + dimmer

    See my website for how to wire up things to a switch (for electricians) 2 way switching etc Electrician - Become an Basically everything at the switch is active and is red. The black wires always go to loop as loop is just a terminal and does not go anywhere. It is just to connect two cuts...
  18. C

    Charging AGM batteries

    Anything faster than charging a battery over a period of 14 hours involves a lot of precautions. You will have problems of heating, generating hydrogen gas, evaporation of electrolyte, reducing cell life, buckling of plates, and more. To charge 2 x 12v batteries in series you will need to...
  19. C

    led lamp assembly help

    Include the 75 ohm resistor and gradually increase the voltage
  20. C

    converter design

    How many A-Hr are the cells
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