is there anything that can be used to reduce car battery current from 12volts to 9or 10volts?

Question

is there anything that can be used to reduce car battery current from 12volts to 9or 10volts? if yes, then pls explain precisly

Answer 1

If your car requires 12v...I would leave it be, but it you must reduce it, just buy a smaller battery or get one from a salvage yard.

Answer 2

Well I hope you don't plan on running the whole car on this voltage. Because that won't work, but the only way I can think to reduce the voltage would be with a resistor. You just put a resistor in line with the component that you are trying to run. As for the size resistor you will need I do not know.

Answer 3

Resistors
The term ballast resistor primarily refers to a resistor which compensates for normal or incidental changes in the physical state of a system. It may be a fixed or variable resistor.


[edit] Fixed resistors
For simple, low-powered loads such as a neon lamp, a fixed resistor is commonly used. Because the resistance of the ballast resistor is large it dominates the flow of current in the circuit even in the face of negative resistance introduced by the lamp.

The term also refers to an automobile engine component that lowers the supply voltage to the ignition system after the engine has been started. Because cranking the engine causes a very heavy load on the battery, the system voltage can drop quite low during cranking. To allow the engine to start, the ignition system must be designed to operate on this lower voltage. But once cranking is completed, the normal operating voltage is regained; this voltage would overload the ignition system. To avoid this problem, a ballast resistor is inserted in series with the supply voltage feeding the ignition system. Occasionally, this ballast resistor will fail and the classic symptom of this failure is that the engine runs while being cranked (while the resistor is bypassed) but stalls immediately when cranking ceases (and the resistor is reinserted in the circuit).

Modern electronic ignition systems do not require a ballast resistor as they are flexible enough to operate on the low cranking voltage or the ordinary operating voltage.

In old AC/DC receivers, the vacuum tube filaments are connected in series. Since the voltage drop across all the filaments in series may be less than the full 117 volts from house's line voltage, it was necessary to get rid of the excess voltage. The resistive component use for this purpose was often referred to as a ballast resistor.


[edit] Self-variable resistors
Some ballast resistors have the property of increasing in resistance as current flowing through them increases, and decreasing in resistance as current decreases. Physically, some such devices are often built quite like incandescent lamps. Like the tungsten filament of an ordinary incandescent lamp, if current increases, the ballast resistor gets hotter, its resistance goes up, and its voltage drop increases. If current decreases, the ballast resistor gets colder, its resistance drops, and the voltage drop decreases. Therefore the ballast resistor tends to maintain a constant current flowing through it, despite variations in applied voltage or changes in the rest of an electric circuit. These devices are sometimes termed barretters.

This property can lead to more precise current control than merely choosing an appropriate fixed resistor. The power lost in the resistive ballast is also minimized because a smaller portion of the overall power is dropped in the ballast compared to what might be required with a fixed resistor.

In times past, household clothes dryers sometimes incorporated a germicidal lamp in series with an ordinary incandescent lamp; the incandescent lamp operated as the ballast for the germicidal lamp. For the same reason, certain older designs of mercury-vapor lamps also incorporated ordinary tungsten filaments within the overall envelope of the lamp

Answer 4

A resister will only lower the amperage. You need a 3 volt load in the postive side before the 9 volt load your going to run. That will knock off 3 volts. Use a light bulb or something similar.

Answer 5

Yes and it depends why you want to do it and what load (Amps) you are trying to produce.
Many cigarette lighter and power port adapters are this voltage. Best bet Radio Shack or JC Whitney
Make sure your tip and plug are the same polarity as your equipment. Radio Shack can help with this and even explain it!