How to control your "points", "turnouts" or "switch machines" on your layout.
Depending upon where you live, you will call a section of track, where one route diverges from another either a "turnout", "set of points", "switch" etc. I normally refer to it as a turnout, or set of points.
An example of a HO scale set of Peco curved points
A solenoid style switching mechanism is one way of switching your "points". That is, a coil of fine wire that create a large enough magnetic field when a current passes through them, to switch the blades of your turnout over. 2 coils are used - one for each possible route setting.
A typical solenoid style points motor
Controlling the solenoids:
The nature of the coil of wire has resulted in a special requirement to switch your turnout from one route to the other. A very short burst of energy (electricity) is required, but cannot be left on, and must be large enough to throw the switch blades. The solution is by way of a "capacitor discharge unit". I don't take credit for the design, it has been around in many variations for as long as I can remember. I am just presenting it in my terms, which will hopefully be understood by somebody!
Basically, a power source charges some capacitors to their capacity. Often, an indicator (such as an LED) shines brightly to show that the unit is ready to do its job. A button or switch is closed, to allow that charge to dissipate through the a solendoid coil and change the point blades over in the process. The circuit does not allow any further current to flow until the switch or button is released, preventing coil burn out or even a fire. Once the button is released, the capacitors charge again, ready for the next use.
An example of a capacitor discharge unit circuit board
If your capacitor discharge unit doesn't quite do the job you expect it should do, a few tips below may help -
So if you are having trouble activating your solenoids - increase wire gauge, increase supply voltage and/or increase capacitance.
An example of a Peco accessory switch. It clips onto the base of the points motor, and can be used as an indicator on your control panel to show route setting, operate signalling, or interlock other points etc