# resistance

1. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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...