1. ### Basic resistor question

Dead right too - I must have been asleep. Any balance condition would do the trick.
2. ### Full wave rectification

The two plates (anodes) are driven by the opposite ends of a centre-tapped transformer secondary winding. The AC potentials at the ends of such a winding with respect to the centre tap are in anti-phase to each other. That is to say, when one goes positive, the other goes negative.
3. ### Max current spikes in diodes

In the situation you describe, with ceramic capacitors of probably quite low values, the inrush current will flow for only a brief period. For instance, with R = 0.1 ohm and C = 10 micro farads we get a time constant RC = 1 microsecond. This is much shorter than the 8.3ms often quoted in a...
4. ### Operation of a P channel MOSFET

Conduction in the inverse direction along a MOSFET channel is generally possible. This is utilised in some types of synchronous rectification, and also in some analogue switches. What is not possible, at least for most (all?) discrete devices, is for the MOSFET to block a large reverse...
5. ### Basic resistor question

If (and only if) all the resistors have equal value r, the bridge circuit simplifies very easily. Can you see what the total would be? Hint, imagine a voltage applied across the network: what then would be the voltage across the central resistor R3? Oops. Berkemann has already pointed...
6. ### Engineering Pmax in the given circuit.

Of course, Vs will not be at its maximum value at all times, but it should not have dropped to anything near 24V unless C was very small, say 47uF. (IT =CV, assuming 8V drop in 10ms at 30mA gives 37.5uF.)
7. ### Engineering Pmax in the given circuit.

You seem to have an incorrect value for Vs. What voltage would you expect across a capacitor fed by a bridge rectifier from 24V AC? Wouldn't you expect something closer to the peak value minus the bridge drop? The answer I get is actually a bit low even if we assume a 30V Zener, so I wonder...
8. ### Bridge Full Wave Rectifier Peak Voltages and Capacitcane Value

A basic statement of Kirchhoff's Voltage Law is that around any closed loop, the sum of the emfs is equal to the sum of potential drops. You need to grasp that idea if you want to make sense of circuits. There is also a diode in the path leading to the bottom end of Rl. It too requires...
9. ### BC183L transistor crossover?

BC183L has a different pin-out to many other types (1. Emitter 2. Collector 3. Base), 2N3904 is NOT the same, according to data sheets I've just looked up. You might be able to bend the leads to suit, but you need to be aware of this. http://www.fairchildsemi.com/ds/2N/2N3904.pdf"...
10. ### Digital Ramp ADC Analysis difficulty

As you know, the resistors are in the ratio R (MSB), 2R, 4R, 8R. To get actual values you will therefore need to decide the value of R. What are the constraints? The value of R must not be too small, or the counter outputs would be heavily loaded: this could do damage, or at least make the...
11. ### Engineering Transitor circuit help

Have you been given information about the type of transistor used, or details of its characteristics, particularly its current gain and its base-emitter voltage? Do you have any values for the DC conditions required, such as the collector current, the collector voltage (Vc in the diagram)...
12. ### Windings question

The wire used in some spiral-wound heating elements is not insulated. In this case, although adjacent turns of wire may look as if they touch, they are in fact held apart in grooves on an electrically insulating heat-resistant former. The design of wire-wound resistors also avoids the...
13. ### To all engineers/engineers to-be!

If I had known how badly the engineering sector was going to decline in my country, I might have kept Electronics as an interesting hobby, and taken up something else as a career. Right now there seems to be only limited opportunities for engineers in the old developed world, particularly...
14. ### Photoelectric effect

Electromagnetic radiation with a wavelength of 180mm would be described as microwave, not ultraviolet! Suspect a typo.
15. ### Exciting Current harmonics in Transformer

The output transformer in an electron tube audio amplifier is rather a special case. Here the impedance driving the transformer primary will be relatively high, compared to that nomally seen by a voltage transformer of similar rating used for AC mains distribution. As a result, harmonic...