The four-wire circuit gets its name from the fact that is uses four conductors to create two complete electrical circuits, one for each direction.

US, AC:The US National Electrical Code only mandates white (or grey) for the neutral power conductor and bare copper, green, or green with yellow stripe for the protective ground. In principle any other colors except these may be used for the power conductors.

Blue and yellow wires are most commonly found in commercial buildings and are used as the live wires pulled through a conduit. Yellow wires are used as switch legs to ceiling fans, structural lights, and outlets paired with light switches, while blue wires are usually used as travelers for three-or-four-way switches.

Green, green with a yellow stripe, and bare copper wires can only be used for grounding purposes. A ground wire can never be used as a neutral, even though it connects to the same bus at the main panel—that’s a huge safety violation that can cause electrical shock, serious injury, or death.

Green with yellow stripe is the ground and will go to the building green. If you are running 220 volt or more then you will probably have multiple hot wires connecting to the fixture’s brown wire and Blue Wire. Remember that you should only run higher voltage if you have to.

Yellow is positive, blue is negative.

If you have a wire where both sides are the same color, which is typically copper, the strand that has a grooved texture is the negative wire. Run your fingers along the wire to determine which side has the ribbing. Feel the other wire which is smooth. This is your positive wire.

12 volts

Step #9: Connect the Wires to the Appropriate Terminals Begin with the 3.3V wire (orange) on the far left, then the 5V wire (red), the +12V wire (yellow), and the -12V wire (blue).

54 watts

110 volts

120 volts

Generally speaking, the motherboard and any circuit cards use +3.3V or +5V, (newer motherboards and processors tend toward +3.3V, while older ones are usually +5V) and fans and disk drives use +12V.

The closest thing to measuring voltages on the motherboard would be to back-probe the 20/24-pin ATX and 4/8-pin ATX12V/EPS connectors to see what the voltages measure at there with a multimeter.

The CPU is made up of three main components, the control unit , the immediate access store and the arithmetic and logic unit .

The laptop internal electronics are powered by a switching regulator from the battery voltage and/or the 19 volts from the AC adapter. This gives a decent run-time for the laptop as the battery voltage drops from discharge during use. This is the ONLY reason for 19 volts.

A pure sine wave inverter works just fine with laptops, but even so, inverters aren’t very efficient for charging laptops. An inverter steps up your 12V to 220V (or 110V), and then the laptop charger will step the power back down to 18.5V, 19V, 20V etc. depending on your laptop.

NO you cannot charge your 12V AGM battery directly with a 19V Laptop power supply. So your fully charged state is about 13.8 – 14.5V. Putting two batteries in parallel does not change the voltage required to charge them it simply increases the current capability (increased Ah rating).

Can I use a 15v plug to a 12v device receptor? In the case of cooling fans the answer is generally yes. Most cooling fans accept a variable DC voltage of between 6V to 23V. Anything else I would say “No.” Wall bricks are cheap at around $6 for a cheapo from Fry’s, and will step down 110V AC to 12V DC in a snap.

will 19v tv work on 12v? nope, it won’t work.

To drop from 15v to 12V at 5amps , that is drop 3volts at 5amps requires a 0.6R resistor, rated at LEAST 15Watts. To be sure it didnt get overheated I would use a 25Watt or higher resistor.

Most 14v models will run fine on 12v.

Resistors in series would drop the voltage. Instead you can connect a resistor in parallel that can draw 180mA of current while allowing 20mA to charge the battery.

1. Simple voltage dropping isn’t efficient, and efficient voltage dropping isn’t simple.
2. The proper solution is a 24 to 12 V switching regulator, at the end of the wire, as you have surmised.
3. You could wire up a relay on a timer to swap between the batteries every five minutes or so.

Putting four resistors in serial and connecting it with 12V power source. Taking voltage only from one resistor; thereby achieving 1/4 of power source from it. take a 12v 4ohms potentiometer where the pointer will be adjusted at 3 ohms so that the voltage at last 1 ohm will be 3v.

If you wire a whole bunch of LEDs in parallel rather than dividing the power supplied to them between them, they all share it. So, a 12V battery wired to four 3V LEDs in series would distribute 3V to each of the LEDs.

The simplest possible step-down circuit is a resistive divider. Drive your 5V output into a chain of resistors, from which you tap your 3.3V logic input. A chain consisting of a 2.2k and a 3.3k resistor should produce a 3V output from an applied 5V input.