Looking for some help on a mechanical design

[Kevin2341]

I'm a junior at my university in electrical engineering and we're tasked with created an original project for my electricity and magnetism theory class. I've come up with something I want to do, however a fair amount of the design for this project is pretty far out of what I know how to do. Anyway, I'm working through a particular part of how I could accomplish this project and was looking for some people who are more trained in this than I am to look over my idea (and perhaps correct me if I'm going the wrong direction).

One of the main parts of my project is that a weight will be raised, held, and lowered. I have the raising and holding design figured out for the most part, but for the lowering part, I am stumped as to how to go about the problem. I want the weight to be lowered at a low speed, as in, when I release the brake, I don't want the weight to drop as fast as gravity will take it.

I am looking for a cable reel which can spool (or raise the weight) unhindered, but when it unspools (lowers the weight), I want it to release at a slow rate (preferably constant rate). I'm a bit uneducated when it comes to the world of cable reels, so I was hoping someone around here may have an idea of what can be used. My original thought was getting a cable reel and then attaching a bike brake or something and have the release regulated like that. My only reservation is that the brake doesn't require any electrical power to operate

Any thoughts?

 

[Doug Huffman]

There are a plethora of old fashioned mechanical regulators. For instance Watts/Farcot flying ball regulator/governor. The air motion regulator as in a music box.

 

[dragoneyes001]

isn't the "winch" exactly what you describe?

http://www.ingersollrandproducts.com/am-en/products/lifting/winches

 

[Kevin2341]

I believe a winch is on the right track for what I need. The system will retract the cord when lifting a weight, a winch would do well due to the built in braking system. I just need a way to slow the extending speed (so that the weight doesn't drop too fast). The goal is to transmit the energy from the weight being dropped to spin a motor and generate electric current, hence why I don't want it to drop too fast. That's why I was thinking a brake like that found on a bike might do the trick nicely, but I'm pretty novice in this field and I'm not sure if its the correct way of going about this.

 

[montoyas7940]

The electrical load on the generator will slow the weight. If you use a mechanical brake you will waste energy as heat you could have converted to electricity.