1. T

    change the voltage range or lower the minimum voltage

    Hello everybody! I have a very basic question, surely I am using the DAC pin of an arduino due, which supplies a voltage between 0.55V and 3.3V, and I want it to supply a voltage between 0V and 5V. how can I do this? Is it possible at least that it supplies between 0V and 3.3V ?. that is, only...
  2. T

    How do I not pass current with 0V input? is it possible to change the input voltage range?

    Hello everybody! I have two questions. I have this circuit where I want to vary the input voltage (V1) between 0V and 5V to supply power to R2. Is it possible to make the circuit not supply a power (0W) to resistor R2 when my voltage V1 is 0V? When I do the simulation with 0V in V1 there is...
  3. Jorne

    input resistance of transformer based power supply

    When I measured the input resistance of some 230V AC to 12V DC transformer based power adapters, I got around 400 ohms. Isn't this quite high for the resistance of the primary winding? I expected no more than 100 ohms. The adapters are low power though (output power< 10W). (Background story: I...
  4. M

    AC resistance of an inductor?

    I measured the AC resistance of my customized inductor with network analyzer of core E70. I got 23mohms AC resistance and 2.3mohm DCR for 14uH inductor with 8 number of turns using litz wire(1400) of 4.3mm diameter. I also got 30mohm AC resistance and 11mohm DCR for 54uH inductor with 16 number...
  5. yverde

    Current limiter for fan

    Hey, I'm am trying to use computer fans for other purpose, I tried hooking one up to a 12v power source and it blew up. The fan was rated 12v, but 0.37A and I used a 12v, 2A power supply, I thought the fan would use only the current it needs, but I was obviously wrong. So my question is can I...
  6. D

    Inductor current

    An inductor of 10H has 1omh internal resistance. What is the current through the inductor after 10V is applied for 1 second?
  7. R

    Why would an underground conductor experience a voltage drop?

    Hello I'm a student and I have conducted an experiment where I buried a wire underground. Since there are many underground conductors in Seoul(where I live), I've always thought whether metal substances from the earth would effect the conductor's transmission. If the magnetic fields of the...
  8. D

    busbar current capacity

    Hi, I wonder how a maximum current rating for wires and busbars are calculated. How the maximum current rating for busbars are calculated, is there any standard for this. I used a copper busbar for my motor connection. but i need how much max current can be passed through it, is there any...
  9. Lambo Av

    Generator protection, calculating resistance for protection

    A 20kV, 100VA generator is protected by differential protection. 70% of the winding will be protected against the phase. What is the value of resistance to be located at the "Neutral to Ground" protection if the relay operates 30% out of the balance current? Below are my steps to the solution...
  10. Lambo Av

    Star-connected, 3-phase, synchronous generator with armature resistance, reactance, leakage resistance. Calculate rated load and unity power factor

    If a 100 KVA star-connected 400 V three-phase, 60 Hz synchronous generator with armature resistance 0.35Ω/phase and 3.5Ω reactance and leakage resistance given is 1Ω/phase. Calculate at rated load and unity power factor at i) No load e.m.f ii) Internal e.m.f. iii) percentage of regulation at...
  11. Alcore

    Finding an unknown resistance

    Hello. This may be a simple problem, but I'm struggling to obtain the resistance R found in the figure below. First what's throwing my are the two voltage sources. I'm used to seeing these present in op-amps, but the way they intersect is throwing me. I'm not sure how to determine their...
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