I'm not sure if something changed in the last 20 years in the brakes [ed. was breaks] system, but I noticed lately that its uncomfortable to press on the brakes, and that most of them start squeaking fairly quickly.

A mechanical safety measure would press the mechanical breaks if something goes wrong with the slowdowner, or if the driver hit the breaks in an emergency.

But when pressing the breaks lightly, for a short time before the mechanical breaks go into operation, the car should be slowed down by an electro-magnetic Slowdowner.

The whole system would last longer, (until the guys that make replacement parts for breaks find a way to shorten them even with this new device).

Another benefit would be energy retrieval.

This whole thing probably exists in hybrid cars, but I'm talking about a device for regular ICE (internal combustion engine) cars, which currently count for most of the cars.
-- pashute, Sep 27 2011

sp: brakes. 'Break' refers to a gap, vacation, or to fracture something into pieces.

There are a few ways to do this, all of which render the vehicle into essentially a hybrid, since you are recovering lost energy and the hardware is already in place, namely hydraulic pressure storage accumulation and electromagnetic motor reversal.

Cars have gotten much heavier over the years due to safety regulations and other factors, but I suspect that the biggest change has been traffic patterns and the number of times your brakes are used.

If your brakes haven't performed as well as your older vehicles, then I suspect you're driving a piece of junk or are harder on them than you should be. Also, material changes in the brake linings to eliminate lead, asbestos linings, and other hazards have also changed their wear pattern, but that shouldn't be terribly noticeable.

Replacement parts are almost never as good as the OEM part. Some (especially brakes) even have to deal with the cost pressures of counterfeit parts in the market which don't hold up at all. Watch out for these.
-- RayfordSteele, Sep 27 2011


//uncomfortable to press on the brakes// Maybe you should stop driving barefoot then? My old car has a very mushy brake pedal compared to newer cars. Newer ones are very touchy and I tend to brake too hard driving them, but it sure beats having to close my eyes in terror at every stoplight. Now that I think about it, maybe I should have my brakes looked at.
-- DIYMatt, Sep 27 2011


Thanks Ray ford pointing me to the spelling mistake.
-- pashute, Oct 25 2011


I agree that if you add an "electro-magnetic Slowdowner" AKA generator, that is capable of serious deceleration, and you're trying to actually reuse the energy (battery, caps, etc), then you might as well make the genreator a motor/generator and have a full hybrid.

However there are a few low cost options that don't make this into a hybrid, and don't add significant machinery to the car, but could save energy and reduce brake wear:

1) Alternator: When the battery is above say 95% charge, the field in the alternator is reduced during acceleration and cruising to allow it to spin freely and not charge the battery. When deceleration is desired, the field is increased above the normal level to provide more slowing and additional charging. When not in stop and go traffic, the alternaotr would need to turn on the field to the normal level to prevent the battery from discharging too much. Taken to far this would require a better battery and bigger alternator, but I suspect some gains could be realized during many driving situations without putting too much stress on standard alternators/batteries. It would also require enhancing some components on the 12V system to handle the varrying voltage better. for example, standard headlihts would get dim during acceleration and cruising, then get very bright during braking as the battery is the fast-charged. This would definitely require a lot more monitoring and electrical control hardware which adds to cost, but doens't weigh much, so this has a chance of having a net improvement.

2) Air conditioning could be handled similarly: Try not to run the AC except when the car needs to slow down. This would be fine when full AC isn't needed, but on a hot day the driver would want it on all the time, so they wouldn't get any advantage unless the AC was bigger so it could provide enough cooling when running intermittently. On a day when no AC is desired, this could still be used to reduce brake wear, but the energy would be wasted.

3) Engine braking (baked), but the energy is completely wasted.
-- scad mientist, Oct 25 2011


It's not COMPLETELY wasted. I enjoy listening to the trucks go BUHduhduhduhduhduhduhduhdadada
-- normzone, Oct 25 2011


AC braking certainly works, as long as the car is a manual and the compressor is mechanically powered. In many cars, turning on the AC simply increases fuel consumption as the computer (annoyingly) responds to the increased load.

I still think regenerative braking using batteries is a waste of time, as the battery wear-and-tear caused by storing and retrieving 1 unit of energy costs more than the 3 or so units of fuel energy that would be saved. Battery power is expensive, wasteful power.
-- spidermother, Oct 26 2011


To slow the vehicle at a useful rate requires that the system moves energy at a high rate. If your engine uses 50HP to accelerate the vehicle at a reasonable rate, then the slowing mechanism must shift energy at a similar rate. This assumes the system is not required for rapid stops, that would still be down to the brakes.

The alternator might be able to shift energy at about 1HP.

Friction brakes are the cheapest and most effective way to stop the vehicle. Regenerative braking is only worth doing if the vehicle already carries the mechanisms needed to effectively recover and store energy. Electromagnetic braking is regenerative braking without the storage (so you need a big heat sink to dump the energy).
-- Twizz, Oct 26 2011



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