3

I think that the power adapter was probably first designed for the North American market. For that market, the design is not flawed.


3

For this specific relay, a quick search returns many results. One of them is from Mouser, an electronics component source. There is a link on the web site for the data sheet for the relay. Some of the information presented on the linked page indicates that this is a single pole double throw relay (SPDT) with a coil voltage of 12 vdc and a maximum contact ...


2

When you bump the plate on a thread off the edge, the plate tilts, inertia of the motor drives the plate to a larger angle. Deformed plastic grips much stronger than what motor can move. To avoid this you need to reduce this bending of the plate due to inertia. You could make a plate thicker. It will bend less. It will capture the motor's shaft less when it ...


2

Considering that this is a class project, depending on what you use to control the DC motor, you might be able to use current limiting. The technique is called current sensing. When a DC motor is running freely then it draws much less current than when its about to stall (see image below) When the current stars to increase that is a signal that the DC motor ...


2

You will need more than a 220V:12V transformer. Fullwave bridge rectifier output: $$ V_{DC} = 0.637\ V_{MAX} = 0.9\ V_{RMS}$$ This is the generic formula (textbooks), which gives you 10.8V. Higher current may cause < 10.8V. Lower current > 10.8V. As in: the actual voltage depends on the load current. From Full Wave Rectifier. The peak voltage of a ...


2

IMHO, this choice is more an aesthetic rather than a functional. Also it offers a choice for a usb charger which is intented to be connected directly to a wall socket e.g. bedside (and not on a power strip). Both designs have pros and cons. Side end photo accidental knocking (+) Better (-) more exposused interferes with adjacent outlets (-) interferes ...


2

Capacitance only depends on its geometry, ... False. Capacitance is also determined by the dielectric (the insulator) between the plates and this can have a huge effect on the value obtained. ... but the charging and discharging of the capacitor depend on a resistive load within the circuit. The load doesn't have to be purely resistive but we'll go with &...


2

I suspect you are talking about the difference between these two TL;DR: Type F is more usable, while type E has more safety prone features Type F advantages The main benefit of the F type is that it can be used at any orientation. So you can approach in two directions which are equivalent. Analogy to USB An analogy to a more ubiquitous pattern is the USB ...


1

Lenovo ADL170NLC3A has an Energy Star V (ES 2.0) rating. Energy Star states to get that rating for nameplate output power ($P_{no}$) > 45W, the Minimum Average Efficiency in Active Mode ≥ 87%. At nominal conditions of 170W, 20V @ 8.5A, and a minimum efficiency of 87% implies 195W input. So worst case, the ac charger consumes 25W. The AC adapter is a ...


1

Your question has several sub-questions. I'll try to address them to the best of my knowledge (there are other people more knowledgeable than me on the subject). Spring Thingie Regarding the spring thingie, I think you are referring to this: Figure 1: mains Tester screwdriver (source: RS website) The idea is that you can use this to test if a socket has a ...


1

I think it's the effect of "tightening the screw", a lot of friction distributed over a large area. Even if the plate doesn't bend, it will still accumulate a bunch of tension, and as a result, friction. You need to stop the motor before that happens. I think a mechanical stop could work: put a small "blade" of sheet metal on the shaft (...


1

They are the extremes of the voltage at the input which define the required 0 and 1 logic levels. On the data sheet Logic 1 must be at least 2.0v and logic 0 less than 0.8 to function properly.


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