Advice 1: How to determine the polarity of the wires

The polarity of the wire is easiest to identify by the markings on the voltage source to which it is connected. However, this possibility is not always available. It could be the wirescoming from the charger to the car battery, the insights of dynamic speakers, wire the power to the radio. Sometimes it is necessary to know which of several network wires phase, and which is zero or ring a cablestretched from one room to another. In each case there is your solution to this issue.
How to determine the polarity of the wires
You will need
  • multimeter, battery, 3 volt, flat screwdriver, pozvonochnye wire.
Instruction
1
To determine the polarity of the wires coming from the charger, turn on the multimeter mode to measure DC voltages up to 20 volts, the black wire (negative) connect to the COM terminal and the red (positive) to the VΩmA socket. Connect the probes to the terminals of the charger and turn it on. If the display of the multimeter there is a minus sign, then the polarity is opposite, that is, the red test lead connected to the negative terminal, black to the positive terminal of the charger. In the absence of a minus sign correspond to the terminals connected to the probes.
2
To check the polarity of the speakers briefly touch his conclusions wiremi from the batteries on 3 volts. When moving the speaker cone outward, the polarity of the speaker terminals match the polarity of the battery. When moving inward, the polarity of the speaker outputs are the opposite polarity of the battery.
3
The power wire to the branded radios are easy to distinguish by color, which always corresponds to its wire. Black color wiresto be connected to the common ground or "minus" of power supply red wire plus the power connected to the ignition switch, yellow wire also refers to "plus" power supply, only connected to the battery. In any case, the wire with the fuse is the "power plus" power supply.
4
When replacing a faulty switch is not always possible to disconnect the house or apartment. In this case, will help to determine the phase (threat) wire flat screwdriver. It will help in the case when at carrying out any repair work you came across an unknown wire.
5
For continuity of the cable with the same wires turn on the multimeter mode to measure small resistances. In the case of continuity of the signal wires as a common pozvonochnika wire you can use a metal screen of the cable. On one side of the cable, connect the studied wire to the screen, and on the other hand connect the black test lead to the braid and touching alternately the wires, locate the closed the wire screen.

Advice 2: How to determine the polarity of the battery

In the automobile sold of lead-acid batteries direct (they are all domestic cars) and reverse polarity (installed on some machines of foreign production). Before buying a battery, it is necessary to accurately determine its polarity.
How to determine the polarity of the battery
You will need
  • Voltmeter
Instruction
1
The service life of any battery is limited and is usually not more than five years. After the allotted time, there comes a time replacement unit. And if owners of cars of a domestic production the problem is to select the appropriate battery capacity and give preference to a particular brand, then the owners of imported cars need to find out before purchasing the polarity of the battery.
2
To achieve this task, the battery is removed from the battery socket and is positioned in such a way that by visual inspection from above its terminals must be at the bottom. Please note that one of them is a little thinner than the other (it is negative).
3
If the negative terminal is located on the accumulator on the left (bottom), the battery reverse polarity.
4
In cases where a thinner terminal on the right battery polarity.
5
To finally verify the correctness of the polarity of the battery, reconnect the voltmeter. The red probe of the device removes the voltage from the large terminal and the black thin. The reading on the scale without the minus sign confirms the studied parameters of the battery.
Note
Install the battery by improper polarity in the car face the fact that its terminals are not be able to attach the cables.

Advice 3: How to determine the polarity dynamics

At first glance, the labeling on the speaker polarity has no meaning, since it is supplied to the AC voltage. But when the speaker system a few drivers, you must include them in phase. Denoted on the findings of the head of such polarity, in which the diffuser is moving forward.
How to determine the polarity dynamics
Instruction
1
Fabricate to check speakers special sampler. To do this, take an ordinary pocket lamp based on incandescent bulbs. Remove the switch and instead connect the two probes. They have to be isolated pens, as in the time of the off voltage at the terminals of the head there is a voltage of self-induction. Check the polarity of the voltage across the probes with a test voltmeter. Coat them with the appropriate designation. Make sure that if the probes are close, the light bulb glows.
2
Turn off the amplifier and all stereocomplex (including and from the socket). Disconnect both output drivers from other circuits to the speaker. Connect the probes to the terminals head without touching neither the last nor the metal parts of the probes. At this point, look carefully at the diffuser. If it moves outwards, and when you disable the interior, the polarity is correct. If the reverse is the case, change the polarity connection of the test leads, then repeat the test. Then mark on the frame the dynamic head of a black permanent marker polaritycorresponding to the polarity of the probes.
3
Carry out the same operation in relation to the other speakers within one speaker system. Regardless of how they are connected (directly or through crossover), connect them in-phase so that the red terminal on the rear of the column was consistent with the positive findings of the heads.
4
Also check and, if necessary, readjust the second speaker system. Closing the housing of both speakers, check that they are connected to the amplifier. On the cable, which is such a compound, there are special red labels. In all cases the conductor labeled connect to red terminal, and conductor no label - black.
5
Turn on stereocomplex. Compare its sound to that which occurred prior to alteration.
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