Hi, I'm a complete noob at electronics and I need your help!

I plan to make a portable circular arrangement of LED's that are powered by a battery pack. I'm thinking about 20 x 1W LED's.

I allready have a bunch of LEDs with these specifications (Pic related):
LED Emitter: 1W
- Output Lumens: 90-100 Lumens
- DC Forward Voltage (VF) : 3.2-3.6Vdc
- DC Forward Currect (IF) : 350mA

So as I understand it I have to wire them up in paralel with some resistors, but I have no idea what resistors to use and how exactly to wire them.

And also what kind of battery pack should I make?

Hi!

So for a project I'm doing i took this motor of a lawnmower that has been sitting out in the open trough several winters.

After doing basic cleaning and checking for water and shit in critical places it seemed good to go and so it was.

Only problem, as soon as the power is applied (or it gets up to rev's) it starts to vibrate or even pulsate unhealthy.

Also, it seems to get rather hot even after 10..15 minutes of runtime.

Is that a problem and what might be the possible cause and fix if so. Bearings seemed to be solid, power consumption is acceptable 1.5A, wirings are dry and show consistent resistance and basic ohm test indicates usable capacitors.

Still, from experience with other motors, when activated with plain spindle, they seem to be near silent - similar to how this motor rotates right as i cut power.

Few things that i could imagine - misshaped plastic fan and threaded axle mount throwing things out of balance, deteriorated (but not dead) cap causing erratic running, sub-par assembly and component precision causing some scraping or eccentric rotation.

It's a lamppost lamp, thin about 2 cm maybe, powered by USB.
Planning to make it light up auto when its dark in the room.

Any suggestions to improve it ?

How many mechanical engineers does it take to change a light bulb ?

A light went out in my bathroom,
can someone point me in the right direction ? What is this, how to change it how much etc.

thanks in advance

How can I cheaply make cool decent tabletop rpg miniatures?

Hey guys I want to ask does any one have any information on how to make a fallout power suit I am very handy good in making things and this is my next project I am just not sure How all the detail look and it is going to be maid in steel so I need to do some homework on that but any help and will share pics when I am doing it

So I bought a straight razor ( or so I thought).
But sharpening it, I can see that the blade is getting sharpened in the middle on 1 side and on the edges of the blad on the other.
So, are some razors meant to be curved and if so, how do I sharpen it?

Anyone know a way to have a 150w amp + pedals powered via a car or some kind of cheap generator? In other words, portable power, not something I have to connect to the car battery itself.

Pic related: I've been looking at this but I'm not sure how it works and if it would work for the purpose I want.

Hi Anons, I need your help. My trk-8200e boombox was working fine just 30 minutes ago until the leds went off, nothing works. Can it be repaired, if so can you guys guide me since im new to sodering and whatnot, Thanks

Anyone car audio/electronic savvy? need help fixing my amp. Rockford fosgate P1000x1bd (pic def related)