Claude,
Sorry for the delay, but I was out of town for the last few days.
"I've been saying the same. I showed in a different thread the function of a switching power supply. When FET is off, catch diode is placed across the input supply. When FET is on, inductor in series with diode. In 1st...
To the Ineffable All,
It takes energy to increase the magnetic field. For instance, a permanent magnetic already has a magnetic field about it, and the energy to establish that field was supplied when it was manufactured. To increase that magnetic field even more is going to require...
Any time a charge moves, a current exists, and a magnetic field if formed (see image below). Therefore, all currents are "magnetizing". Magnetic fields are concentrated by forming conductors into coils.
A phase difference means reactance is present. If you are talking about a series...
I am leaving for Las Vegas, Nevada tomorrow evening to visit a friend (not gamble). I shall return April 1 (not a joke). Everyone enjoy my absence.
Ratch
No, it is stored and released in the electric field of the capacitor and the magnetic field of the inductor. The reactive power is taken in and given back to the circuit twice each cycle. A perfect capacitor or inductor will not consume any resistive power (heat) . That is true no matter what...
Depends on what you mean by "work". Unless you have a transformer that doubles the voltage from 110 to 220, the shaver is going to operate at only one quarter power at 110 as it did at 220.
Ratch
When you say something is lagging or leading, you should specify what (voltage or current) is lagging or leading. Anyway, yes, a circuit with too much inductance can be corrected by adding a capacitor to the circuit. That is called power factor correction. There are plenty of references on...
The second equation involves Q, R, fr, and L . You know what Q, R, and fr are, so you can find L. The first equation involves fr, L, and C. You know what fr and L are, so now you can find C.
Ratch
"I've been saying the same. I showed in a different thread the function of a switching power supply. When FET is off, catch diode is placed across the input supply. When FET is on, inductor in series with diode. In 1st case, V controls I in the diode. In 2nd case, I controls V. I've stated many...
Two identical BJTs with the same Vbe will pass identical currents when operated in the active region at the same temperature. That is because BJTs are transconductance devices. Identical BJTs will have the same transconductance gain. See image below.
Ratch
The circuit you submitted is called a "current mirror". That means the current in Q1 is the same as the current in Q2. You know that is true because both transistors are identical and their Vbe's are the same. Since a BJT is a tranconductance device (voltage controls current) and the Vbe's...
Who cares about that? Ref is in the collector circuit of Q1.
No, IRef = Ib2+Ib2 , but who cares?
Why get hung up on current? You know what the current is supposed to be in Ref. That's a gimme. And you know the voltage at each end of the Ref. Why can you calculate the value of Ref from...
Find the current as shown in the attachment. Then multiply by R to get the voltage. Easiest to find the current by Laplace transforms, but the classical solution is shown in the image below.
Ratch
Yes, the current in the 4k3 resistor is less than the current in the 1k5 resistor. That means current has to be supplied by the LDR. Mathematically, that means the LDR has to have a negative value.
Ratch
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It doesn't matter how many degrees, schooling, or experience you have. If you ignore the physics of a device, you will never understand how it really works, even though you have a good grasp of how to make a device do something useful.
That is where you are going off track. Just because...