Motorcycles and other motor vehicle has a generator car, with the engine connected to electric generator for charging the battery issue or a lit lamp, produced by the generator voltage and the speed of the engine, the engine rotation speed, the output voltage over low and high-speed rotation engine, the output voltage is higher, according to measurement, the output voltage can be varied between 20V-60V, output voltage is stable, now commonly used in electronic regulator device connected between the generator and the load, often called for the Regulator. This Paper describes a Motor Regulator, the INPUT Voltage is 20V-60V, output Voltage is 12V, and adjustable Maximum output Current up to 8A.
Complete Regulator Circuit shown in Figure 1. Is actually a STEP-Down Regulator DC / DC Switching Power Supply. The core Regulator is the Pulse width modulation (PWM) IC TL494, TL494 is a common
Integrated Circuits PWM. Its external pin shown in Figure 2

TL494 pin function as follows: 1,16 and 2,15 feet foot sub is not an error amplifier and error amplifier 2 inverting input and inverting input; 3 pin is the feedback input terminal; 4 feet is the dead time control terminal ; 5,6 feet respectively connected to RC oscillator timing capacitor and resistor; 7 feet grounded; 8,9 feet 11,10 feet are two internal drive transistor's collector and emitter; 12-pin power supply positive terminal; 13 pin as an output state control terminal, when the 13 foot high, two internal drive transistor alternately turn, when the 13 pin is low, while the two internal drive transistor turned on or off, this time can only control a switch tube. 14 feet is the IC internal 5V reference voltage output of the output. TL494 at work, the frequency in the 5-6 feet from the external timing capacitor sawtooth oscillator and resistor, the output pulse width by 16 feet added to the 1 and the error amplifier inverting input level is decided. Inverting input 2 and 15 feet through the R20 and R5 connected to the reference voltage output of 14 feet. Voltage regulator voltage regulator control: the output voltage from the output of energy storage inductor L, through the R23, R7 TL494 received the same error amplifier inverting input 1 1 feet, when the output voltage increases, the feet with the inverting input 1 level rise, will enable the integrated circuits within the two internal drive transistor output pulse width becomes narrower, thus reducing the output voltage. Instead, you can increase voltage. Over-current protection control: over-current sampling resistor is R18, where the output current, R18 is the voltage on the low left high right, which the voltage across R4 and R22 added by the error amplifier 2, 16 and 15 feet, when the R18 the result of over-current and the voltage increased to a certain extent, you can narrow the output pulse width, and thus play a limited output current purposes. Because it is 13 feet grounded, while the two internal drive transistor turned on or off, so the two internal drive transistor is a parallel output, 8 feet and 11 feet connected to 9 feet and 10 feet connected to 9 feet 10 feet to the emitter output 9 feet and 10 feet when the output pulse, VT6 conduction, VT5 end, VT4 conduction, VT3 is also conducting an output current through the inductor L to the load; as 9 feet and 10 feet to stop the output pulse, VT3 deadline, the self-inductance phenomenon VD6 freewheeling diode conduction, the energy storage inductor L stored in the magnetic field energy into electric energy supply of the load, the step-down switching power supplies, freewheeling diodes are indispensable components, without it, power VT3 transistors and other components will breakdown damage. Freewheeling diode is often used fast recovery diode or Schottky diode. To ensure the reliability of the work, composed by the VT1 TL494 voltage regulator circuit for providing starting power; the VT2 regulator circuit consisting of power transistors to provide startup power, once the output voltage has already been established by the VD4 and VD5 direct power supply. Introduced by the above-mentioned principle, the size of the output voltage regulation can be achieved by changing the resistance R23; overcurrent protection current limit control by the over-current sampling resistor R18 determine the resistance. Output power transistor VT3 VMOS power FET with, such as inadequate or too power transistor output current, overheating, two power FET can be used in parallel, but the other FET gate G have a 10 ohm series then the emitter connected to the VT4, the two power FET's drain D and source S are parallel. Output power transistor and freewheeling diode should be an external radiator.