Redstone, Rails, and More - The Ultimate Player's Guide to Minecraft - page 181

1. The cobblestone emits weak power, sufficient to activate the lamp and other
devices, but not enough to power the wire leading to the second lamp
2. Running wire over a block continues the current through the space above the
block
3. The lever provides strong power to the block, firing up the wire
FIGURE 9.4 Strong and weak power.
It's also worthwhile mentioning that a wired connection between a power source and
a device isn't always necessary. Most of Minecraft's blocks—the opaque ones—can be
powered directly by a source. This enables the creation of very small circuits. I included
one example of this in Chapter 6 , where the piston was powered by a button placed on a
block. I'll show you some other examples later in this chapter.
Most redstone sources are attached to a block of some kind. For example, buttons are
placed on the vertical surface of a block such as a wall, a lever to any surface, or even the
ceiling.Generallyspeaking,thesourcepowerstheblocktowhichitisattached(the anchor
block), and this can then activate any devices adjacent to it. This is why a button placed on
ablockbesideadooropensthatdoor.It'snotthebuttonactingdirectlyonthedoorthrough
some hidden link. Rather, pushing the button powers the block to which it is attached, and
that block being adjacent to the door triggers it to open.