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Affected Party

2024

Video: Affected Party

Video: Affected Party
Video: AFFECTED ODDSHOTS - Big J skáče na párty do davu LULW 2024, March
Affected Party
Affected Party
Anonim

The car body is most often made of steel. And since it conducts electric current, designers quickly learned to save on negative wires. Does the aforesaid mean that a minus is less important for a car than a plus? Of course not. But some features of the circuit are useful to know. For example, when “ringing” a section of a circuit through a switched off consumer - a lamp, etc. - A sensitive tester perceives them as "ground." Incandescent filament (especially a powerful lamp) - a good enough connection!

Electricity consumers on the car are connected in parallel, and if the circuits are working, the correct voltage is applied to each light bulb or motor - the first one glows in accordance with its power, the second buzzes briskly. Everything happens according to Ohm's law for a section of the circuit: I = U / R, where U is the supply voltage (12 V or slightly higher when the generator is running), I is the current strength, R is the resistance. (Hereinafter, we assume that the power of the power source is sufficient to maintain the required voltage.)

But if the connection with the "mass" of the machine is broken, chaos may reign in electrical equipment. In this case, some consumers are connected in series, although the supply voltage to such a circuit comes the same - 12 V. And the "riddles" begin. For example, a lamp of a lantern or a headlight when the engine cooling fan is on glows completely, and the fan itself barely shows signs of life, threatening the engine with overheating. Lamps of a stop, backlight, etc. can wink to a step indicator. It is obvious that the power, although weak, in these cases comes to the lamps - but where from?

The problem arose largely due to the fact that there are few real places for grounding the wiring to the body. If each bulb had a reliable “minus” connection, they would not have presented any surprises. But the car, alas, will become more expensive.

We give part of the electrical circuit of a typical car with its sores. Let's see how and why electrical appliances sometimes work in such a strange mode. Any electrician-practitioner knows that in each case the reason is the poor connection of the negative wires with the “mass”, up to its complete break (though this event is rare). More often in the contact of the wire with the “mass” due to corrosion, resistance arises, much more than the designer who designed the wiring assumed - and yet no one has managed to completely defeat the corrosion. Do such troubles happen to foreign cars? Of course. But still less than ours. The wiring is done wisely, and assembled more accurately.

The grounding areas of the visible part of the electrical equipment are not so many: four to five or a little more. Usually each headlamp and taillight have it, in addition, the “minus” of the battery is connected to the car body, the “minus” of the starter is with the engine, and the last is connected to the body, otherwise the starter will work poorly or completely fail. One of the signs that the devices are not in contact with the ground is the “inexplicable” inclusion of indicators on the dashboard: if, for example, when you press the brake pedal, the “dimensions” indicator flashes, this should alert.

It is useful to recall the wiring connections with the body from time to time - to clean, lubricate, tighten the connections. Although we give some examples of failures here, in practice it hardly makes sense to deeply investigate the cause of each - it is usually easier to tidy the wiring.

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ELECTRICAL SCHEME FRAGMENT:

1, 12 - lamp repeaters direction indicators; 2, 11 - direction indicator lamps in headlights; 3, 10 - front side light bulbs; 4, 9 - lamps (or threads) of a high beam; 5, 8 - lamps (threads) of a passing light; 6 - fan; 7 - a lamp for lighting control on the instrument panel; 13 - winding of the ignition relay; 14 - reverse light switch;

15 - brake light switch; 16, 24 - indicator lamps in the rear lights;

17, 23 - rear side light bulbs;

18, 22 - brake light lamps; 19, 21 - reverse light lamps; 20 - license plate light; I, II, III and IV - the main grounding points to the "mass".

Suppose that the connection of the negative lead of the left headlamp with the “mass” at point I, in our circuit itself, has been oxidized. Because of this, when you turn on the powerful fan 6, the current it needs cannot, as expected, go to the "mass" of the body. Through the oxidized compound, heating it, it is possible that some of the current will go away, and the other through the filaments of lamps 1, 2 and 24 (emergency lights on the left side) will fall to minus through grounding III, causing a more or less weakened glow of these lamps. Another part will go through the threads of lamps 3 and 10 of “dimensions”, as well as through the control lamp 7. The latter can burn quite brightly - it is low-power, even now it has enough power. Part of the current through the threads 4, 5, 8, 9 of the main and dipped beam is supplied to ground II. Those lamps that were connected in series in this situation divide the voltage supplying this section, in accordance with Ohm's law: more voltage drops to low power - they glow brighter. The dipped and main beam threads may not burn at all - they are the most powerful, their resistance is minimal. The fan, whose power is approximately 200 watts, in this game is the most “hungry”: it spins barely or is completely inactive.

But if instead of a fan you turn on, for example, the dipped beam? The picture is different. The current consumed by the left headlight now goes along the “near” thread 5, and from it - first along the “far” left 4, and then along the far right 9. If we assume that thread 5 is at least slightly lit, then both far ones are unlikely whether, the voltage drop on them is very small. But the low beam of the right headlight is normal, because the full voltage is supplied to its thread. Of course, part of the current will also go through the threads of lamps 2, 1, 24 on the left side of the machine, and some meager power will go to lamps 3, 7 and 10.

And here is another trick! If the grounding of the III rear left lamp is lost, then when the brake light is turned on, the lamp 22 with a power of 21 W barely smolders - in a series circuit with it are two the same power of the reversing lamp, and in parallel with them are the other (23, 24, etc.) But the right “stop” (lamp 18) lights up normally. When the reverse gear is turned on, the picture is similar, only now both stop lamps - 18 and 22 are connected in series with its left lamp. But the right reverse lamp 19 lights up normally. A low-power (5 W) lamp of 23 left side light, if turned on, burns almost to full heat, because the filaments of the rest - powerful 21-watt lamps provide it with sufficient grounding.

It turns out that operating in reverse or with brakes, the car can be likened to a Christmas tree, since the lights are colorful!

By the way, a situation is possible when the engine does not stop when the ignition switch is turned off. This mainly applies to Russian carburetor cars with ignition relays. If reverse gear is engaged (clutch is depressed) and the brake pedal is depressed, voltage from switch 15 through the threads of lamps 22 and 21 is supplied to switch 14, and from it to terminal 85 of the ignition relay winding. Nevertheless, the voltage that has "sat down" after the lamps is enough to keep the relay, consuming a very small current, about 100 mA, on - the ignition is working. But if you release the brake or turn off the transmission, the motor will stop. By the way, in this mode, the generator control lamp (it is not on the diagram), which remains without a plus from the ignition switch, but with a plus from the generator, will light up brightly.

REMEMBER TO SOME READERS “ABC” TRUTS

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The power of the consumer (for example, a lamp) is the product of the consumed current and the supply voltage. (Power 1 watt = 1 volt. 1 ampere). If the powers of two lamps in a series circuit are equal, then both shine the same way - full light. At different powers, the weak burns brighter than the powerful.

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In this scheme, a connection was made between point A and "mass." This led to the fact that the 21 W lamp shines completely, and the 2 W lamp was out of work - the current does not pass through its filament (minus at both ends of the filament).

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