# Tag Info

16

A contact microphone is basically an accelerometer. It does not require any air for its operation.

6

if it is mounted on the same surface with the same vibrations, it in theory should measure nothing. When sound waves propagate through solid material, it's not just the whole rigid object shaking back and forth: It's waves of strain. Those strain waves will pass through a contact microphone that is attached to some small area of the surface. It will work ...

6

Is it possible to use a 2.4GHz magnetron as a oscillator for a Tesla coil? The short answer is no, definitely not. The long answer is... well, long. Note that the following reasons are each, by themselves, absolute show stoppers. Only one of them would need to be true to make a 2.4 ghz Tesla coil totally impractical. Unfortunately for this idea, the ...

6

Tesla/SpaceX had probably removed the battery pack, electrolytic capacitors, other parts that aren't compatible with vacuum and don't die gracefully. Your question are asked a lot by people who build CubeSats. A lot of them are build with automotive, commercial, industrial components, because CubeSat budgets can't afford the officially space rated parts. ...

4

In addition to the thermal issues with the led bulbs themselves, you may also have issues with the bulbs outgassing. You haven't specified what you're doing in this vacuum setup, but if it's anything that is sensitive to contamination (various deposition processes for instance) or involving sensitive optics, then you definitely need to be careful to select ...

2

One effect related to power converters in space: The thermal grease, the layer between power semiconductor module (of the inverter) and heat sink, disapears quickly into vacuum and the thermal resistance increases accordingly. This results in much higher junction temperatures if the motor would consume power. This reduces power semiconductor life time ...

2

but I have talked to a few people who are experienced in electronics, and they have suggested using mosfets or PWM for powering long nichrome wire coils. That is what I would use to design a circuit to control a nichrome coil too. But as your instructor already mentioned, you don't need to design your own circuit. Read on... (304V at 2.4A to reach ...

2

I am trying to control the power of a vacuum pump using a 10k potentiometer with 12v as its input source. Let's say, for ease of mathematics, that your vacuum pump is 24 W so it will draw $I = \frac {P}{V} = \frac {24}{12} = 2 \ \text A$ when connected directly to 12 V. The current through a resistor is given by $I = \frac {V}{R}$ and at 10k you ...

1

so is this the inrush current of this motor? YES 300% of the rated current is common for start surge of a low-efficiency motor. (high-efficiency BLDC motors use 10x to 12x rated current for start surge) I need the causes, and if possible I want to know what is the proper way to solve this problem? Is it good to use soft starter? You may have damaged ...

1

I feel like that is a really bad idea, and that there should be some extra safeguards. You are absolutely right. The problem with any coil directly connected to mains is that accidentally touching any part of it can be dangerous. And, unlike space heaters, the coils are usually exposed over large surface area. So, apart from obvious mechanical solutions, ...

1

MOSFETS are too complicated (relatively) for a simple task like this, all you need for a heating element is an SCR control, hence the suggestion of a "dimmer" because most dimmers are just a simple triac device. You could also use a simple cheap SSR (Solid State Relay) that does Time Proportional Control, that way you could automate this if necessary, i.e. ...

1

Pickups, like the ones used in guitars, are not strictly microphones. They work on a similar principle, but are coupled in some way to the object producing the vibration. I'm not sure exactly what kind of pickup you are thinking of, but I'm aware of two primary kinds: Magnetic Pickup Piezo Pickup In the case of the first, the magnetic field inside the ...

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