| MadSci Network: Other |
This is actually fairly obvious and simple. All that is happening is you are replacing the 12 volt direct current voltage a car phone charger normally operates on with a 9v direct current battery. The car phone charger contains a small electronic device known as a voltage regulator that will convert a range of DC voltages to a different and steady DC voltage. Regulators are specifically a device that will accept a range of input voltages whilst maintaining a steady output voltage. Remember the car charger usually is connected to your car DC system. This will operate between about 12 and 14 volts DC in most cars. The car battery is nominally a 12v battery but the charging system will run above 12v when the engine is operating. This is because you need a slightly higher voltage than the battery voltage to charge the battery. When the car engine runs the generator and rectifier will produce about 14 volts DC for running your car electronics and for charging your car battery. The car phone charger can accept a range of input voltages and maintain the correct output voltage for charging a phone. The car phone charger is a device that plugs into a cigarette lighter socket in your car. It is a device that converts an input DC voltage of the car to about 5.5 v DC for charging smart phones. Here all we are doing is replacing the car DC system with a 9v battery. The electronics in the regulator can still maintain the correct output voltage with the slightly lower 9v input voltage. You can actually make your own charger quite easily. Voltage regulators for the task can be bought off the shelf from any store that sells electronic components. See here http://www.instructables.com/id/Cell-phone-charger-from-an-old-9V-battery/
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