1, motor drive circuit

The printer motor is a 4 phase unipolar PM step motor (see below), and the step signal (pMMPAOA to pMMP3A) is transmitted from the SHINE IC3 output port to the IC38 (clipping drive circuit). The clipping current depends on the voltage of IC38 (3) and 13 feet, and the printer motor has two kinds of speed, slow and constant speed. The printer motor is powered by +24VDC power supply. When the circuit is open circuit, the +24VDC power is cut off, the motor stops running.

Motor driving circuit

Fixing the lamp drive circuit: fixing lamp by 100vac (200VAC) power supply it on the LVPS drive (circuit diagram), nssr signals by SCPCB. When LVPS CN103 11 feet (nSSR) is low, fixing on the light. This light PC102LED, activation TRC100 photoelectric controllable silicon, and 115VAC will reach the fixing lamp, and TRC100 real activation of time depending in 100vac (200VAC sine wave, when PC102 of 6 feet and 4 feet cross voltage is 0V (sine wave over the OV), PC102 inhibition excitation silicon controlled, open the fixing lamp.

Fixing the lamp driving circuit

2, fuser temperature control circuit

Fuser temperature by SC PCB IC1 control circuit (see below), which includes a / D (analog / digital) converter AN10 to AN17. Fuser temperature control circuit using A/D converter -AN11. When PCO01 drive current from SC PCB is transmitted to the LVPS (PSU), fixing on the light, ic32 is a comparator, the 1, 7 feet for open circuit output is an abnormal temperature detection circuit. When activated Q44, ic32 7 feet with high impedance, open the fixing lamp when the Vth voltage level is above the V + detection for temperature anomalies, which prompted ic32 7 feet lower, Q44 stop working, the abnormal low temperature and high temperature and thermal resistance broken open state is detected by a IC1 (CPU) testing program.

Fuser temperature control circuit

3, high voltage driving circuit

High voltage from DC to DC converter (see below), the converter will supply the +24VDC voltage to -650VDC, and the charging module output about 0.64KVAC (stable current 200 A). By developing a developing bias circuit will +24VDC to about -300VDC, 1.650kHz output 1500VAC (P-P) on toner charging. The transfer circuit converts the supply voltage of +24VDC to about +280VDC (maximum) (stable current 3 A/-1500VDC).

High voltage driving circuit

4 power circuit principle (figure for switching power supply schematic diagram)

(1) input circuit

AC line voltage pass line filter to reach the rectifier circuit. Line filter removes the RFI noise, or the noise may reach the AC line from the power supply unit. It also shield those who may be from the AC line into instantaneous power supply unit in variable noise, to protect the power supply unit.

(2) rectifier circuit

Dl00 of AC power supply rectifier, AC power by C103 generate high DC voltage and then on converter circuit power supply control IC (IC105) out of voltage R134, r135 and R136 by AC power, starting current by TH100 restrictions.

(3) converter circuit

Contains in the transformer Tl00 IC IC105 using RCC (ringing choke flow ring type converter) to form a circuit of switch power supply system, power supply to reach the power supply unit, the AC line voltage that the D100 rectifier and the C103 capacitor to smooth. The protection circuit is controlled by IC105 and resistance R134~R136.

 

(4) the main switching circuit

In the circuit above, when the main switching transistor Qloo is opened, the primary coil of the transformer Tl00 will is supply with input voltage EI, and no current will flow through the secondary coil of the diode d102. The reason is that the reversal of the secondary coil electrode will lead to T100 in no current flows through the. But the transformer is still full of energy. When the Q100 is closed, the voltage of the primary coil is cut off, the Tl00 electrode is changed, the D102 is run, and the energy accumulated in the T100 is released into the circuit. When energy through the release of d102, open the Q100, T100 electrode coil again change, create a self oscillating circuit, in the actual circuit, by changing the proportion of coil transformer T100 modify the output voltage. In the converter circuit, the voltage stability is made by controlling the time of the transistor ON and OFF. In this power supply, the bias coil is built into the transformer. Power supply has four output: +24VDC, +5VP, -5VDC and +5VDC. + 24VDC output by the error detection circuit protection, + 5VDC, +5VP, and -5VDC output by the voltage regulator IC within the loop protection.

(5) control circuit and error detection circuit

Control circuit according to the error detection circuit detection of the error voltage to enlarge the output of the work cycle, it also drives the main transistor Q100. The method used to change the work cycle is to change the length of the ON. When the output voltage of the C circuit is increased, the PC103 current of the photoelectric coupler is increased, the output pulse width of the control circuit is decreased, and the time length of QlOOON is shortened. The control circuit itself determines the minimum OFF time. When the oscillation frequency is high and the time period of OFF is changed to the minimum, the time period of OFF will remain the same, only ON time Duan Zengda. Thus, the oscillation frequency has an upper limit, and the working cycle is expanded.

(6) overload current limiter

+ 24VDC output by TonMAX (transistor Ql000N period of time) limiter limits, ton Max limiter is a part of the control circuit, the voltage regulating device internal control +5VP, -5VDC and +5VDC output overload current limiter.