[Note: Most of this class involved a "show and tell" of trailer brake and controller components, and a detailed description of wiring schemes]
The most common trailer brake systems are Dexter (has two springs across the top) and Hayes (has a single spring across the top). The basic design hasn't changed in 30 years. Only the lever and magnet have changed. When the magnet energized, it activates the brakes. Each magnet draws 3.0 - 3.5 amps. In general trailer brakes are not self-adjusting. In Europe it's code to have self adjusting brakes plus parking brakes for all trailers.
The best rule for handling grades is speed reduction before you start down, and then use gearing to retard speed going down. It will have an enormous impact on brake life. With new trailer brakes, drive a few hundred miles and always make easy stops. After the first 5-10 stops you will be getting much more braking power, and you'll need to readjust the brake controller.
Note: If you ever want to test the breakaway mechanism, be sure to disconnect your cord from the trailer to the tow vehicle first. If you don't, you're likely to burn out the brake controller.
The only true brake controllers are made by Tekonsha and Hayes. All others, (Draw-Tite, Reese, Tap, Jordaon and AccuPower are Timers/Activators, and are much less safe and effective.
Brake Controller and Timers work differently. Brake controllers, set the gain (amps) according to the weight of the trailer, and the level of braking power used. According to the instructor, these "timer" style brake controllers operate in a way which are not capable of responding to the requirements of a panic stop.
When setting up a brake controller for the first time, set the gain to 50-60% for starters. Tow the trailer at 20 mph. With your foot on the accelerator going 20, use the manual brake controller override. If skidding occurs, reduce the gain and retry. If braking is inadequate, add gain and retry. The level on a Tekonsha is right were the red light goes almost off (flickers). Note: A trailer which has been parked for a while will always be aggressive when you first start up. Don't change it to lower power, as it will shortly warm up, clean itself up, and go back to normal.
Tekonsha's top line is the Sentinel. It requires a different type of setup. It provides feedback via LED's showing precisely how much power is being applied to the trailer brake. It also provides LED feedback showing the trailer brake is actually connected; and it will provide information as well on warning conditions suggesting something in the trailer brake system is not functioning properly.
[Our recommendation would be that in the future, this course be divided into two separate sections. One would be the "theoretical", for those who wish to learn the hands on part of installing and servicing trailer brakes and controllers; and the other would be the "practical", which would be a non-technical discussion of how to select, adjust and use brake controllers effectively and safely.]