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# Tag Info

8

The link that you provide and the comment by John D say what must be done. The armature and field connections must be reversed with respect to each other. In the diagram, you disconnect the black lead and the red lead from the two brushes and reconnect each to the opposite brush. The two red wires going to the field assembly are two wires, not one ...

4

No, it will not. The circuitry of a boost converter is not set up to take in power, only output power. For that you will want to search for a buck converter, instead of a boost converter. https://www.amazon.com/s/ref=nb_sb_ss_c_1_8?url=search-alias%3Daps&field-keywords=buck+converter&sprefix=buck+con%2Caps%2C233 however, most don't accept ...

3

Actually I think that none of the components you've circled in all the schematics are responsible for the reverse voltage protection at all (as you correctly pointed this out yourself in all three cases: "diode D1 blocks excessive positive voltage from the input supply", "R5 to block excessive currents from passing to the GATE pin in the event of excessive ...

3

The approximation is good enough because $V_{be}$ is a lot greater than $V_t$ (thermal voltage at a room temperature of $27^o$C). $V_t\approx 26\text{mV}$ at $27^o$C. Even for a value very close to zero, the approximation works well because the exponential term grows much larger than 1. Say $V_{be}=100\text{mV}$ (which is very close to zero), ...

3

At that frequency you have this... simulate this circuit – Schematic created using CircuitLab

3

The thing that i need to make this work is that the ignition lock needs to be open (let eletricity pass trough) when the key is turned. First some terminology: When you close a switch electrical current can flow. When you open a switch the load is switched off. You must have measured the switch incorrectly. All ignition switches will isolate and turn off ...

3

I have ordered a Wi-Fi switch named Sonoff. I have a doubt whether the device will work if the polarity is reversed or will it get damaged? It will almost certainly work It will almost certainly not be damaged IT WILL LEAVE YOUR APPLIANCE LIVE WHEN TURNED OFF. If I'm correct, AC doesnt have polarity right? Most AC supplies have one side referenced ...

2

While synchronous (two MOSFET) boost converters can indeed convert bidirectionally, your board isn't necessarily of the synchronous switching topology (it could use a diode instead). In addition, that board certainly won't be regulating the input side so don't expect 12 V at the input. If it's set to produce e.g. 60 V and you backfeed 61 V it'll try to ...

2

Yes, the ESC you bought will drive the motor. The motor is 3 phase BLDC. The only problem you may have is that the ESC is low torque startup (it's designed for a Heli/quad copter. However given the large 10:1 gearbox you may be ok. If you need high torque at low starting speeds you really need a BLDC with Hall Effect position sensors To add from your ...

2

A BJT is obviously more complicated than your equation(s) provide. But those equations are often good enough when just considering the forward active region. To get a feel for the simplest DC model that was developed, see my answer to Why is Vbc absent from bjt equations?. Today, the term $I_S$ is usually implied to take on the meaning used in the Ebers-...

2

If you need the voltage just for indication or measurement then a simple DC differential amplifier with unity gain will do the job, because the output voltage is 10V minus input voltage: $V_{out} = 10V - V_{in}$. : simulate this circuit – Schematic created using CircuitLab Note that this circuit is not easy to build as it looks even for an ...

2

It's not presented. You might be able to extract it by curve fitting Figure 4, which shows the typical relationship between $V_{BE}$ and $I_C$. Even easier, you can find a SPICE model for 2n2222, which will likely include a reasonable value of $I_{ES}$ determined by a similar curve-fitting technique.

2

1) Are they ceramic capacitors? The capacitors in the photo of the link appear to be 0603 ceramic capcitors. 2) is correct the procedure of unsolder and measure? Yes, usually the best way is to unsolder because the other parts of the circuit are in parallel with the capacitor. By taking it off the rest of the circuit is not measured. I do this all the ...

1

The case for surge protection is disconnection of the battery +ve terminal with an inductive load that results in a negative spike. The Gate voltage limit is due to the Schottky diode protection built in that cannot tolerate more than 1 mA or so external negative input at that voltage in order to protect the CMOS driver against the common SCR substrate ...

1

Given that you are storing in a battery, I assume you are using a dynamo. Dynamos work by using the motion of a conducting coil in a magnetic field. This induces current in a specific direction in the coil. Reversing either the magnetic field or the motion of the coil inverts the direction of the current. So yes, it is reasonable that once you getting ...

1

This current is due solely to carrier generation within the depletion region due to phonon interactions creating an electron-hole pain every once in awhile. Once this hole and electron are generated in this region of high electric field, they are swept in opposite directions. Since there's so few carriers being generated due to thermal interactions generally,...

1

A basic 2-wire synchronous motor will start randomly in either direction, or may fail to start at all. Usually, cheap uni-directional motors, as used in clocks for instance, have a mechanical spring/cam arrangement that engages if the motor starts in the wrong direction, and flicks the armature into the other direction. A synchronous motor may be built ...

1

Without knowing the pinout of your DPDT switch it's difficult to say for sure, but from the image it appears you are indeed shorting out your battery through the switch. I also don't see how the microswitch is working. Can you try to redraw your circuit using standard schematic symbols? It will be much easier to see and understand the functionality of your ...

1

According to its description and my experience buying in Banggood it IS a brushed motor, so reversing its direction is possible (although DC motors lose a bit of efficiency when their direction is reversed).

1

I will assume you are in the US and therefore under the NEC. Based on that assumption, my answer is: There is a difference between grounding and bonding, and this is one of the most confused sections of the NEC. Grounding is intentionally tieing something to earth, whereas bonding is making everything electrically continuous... so we create a grounding ...

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