Power supply for 3D printer

The stable voltage of the +36V power supply of 3D printer series is completed by optoelectronic coupler PC2, transistor Q91, Q3, Q2, etc. As a result of load or other reasons make 36 v + 3 d printers power supply voltage rise, after the R92 and R93 to Q91 base after partial pressure, increase the base current, Q91 c current rise, PC2 in the light-emitting diode brightness increased, light activated triode resistance decrease, current increase, the R20 make injection precision zener diode IC1 R very current is added, Icl cathode potential drop, Q3 c current increase, increase the degree of Q2 conductivity, Q1 G very potential drop, Q1 drain current decreases, and thus make + 56 v power supply output voltage drops, Maintain the stability of +36V output voltage.

The power supply of the +36V 3D printer is connected to the CN2 socket on the main circuit board through CN2, and sent to IC6(A6615SED) after filtering by C37 and C57,27 and 40 feet, and output the +5V power supply from 13 feet after voltage reduction, which is used by the control circuit after filtering by L1, C46 and C39. The other function of IC6 is to supply power to the print head drive motor and the paper feeder motor. This part of the circuit is shown in the B dotted line frame in figure 1. To ensure the reliable operation of the 3D printer, the C4X power supply is equipped with multiple protection circuits.

100W12V照明亮化开关电源120W12V照明亮化开关电源

1. Overvoltage protection
(1) overvoltage protection of mains power. If the mains voltage increases, +300V dc will increase accordingly. The current sent to control pole R of lC1 via R22, R29 and R20 will increase accordingly. The voltage sent to control pole R of Q1 via Q3, Q2 and B1 will decrease so that Q1 will stop and the power supply of 3D printer will stop output +36V dc.
(2)+36V and +5V overvoltage protection. If the voltage stabilizing circuit of the power supply of the +36V 3D printer fails and the voltage stabilizing function is lost, the voltage of the power supply of the +36V 3D printer will greatly exceed 1336v, so that ZD52 and ZD87 will break down the conduction, and the voltage will be sent to the base pole of Q82 through R82 to conduct it. Q82 conduction after Q83 base potential drop, Q83 conduction, on the one hand, make PC1 led current increased, PC1 internal photocell resistance decreased, Q31 conduction, Q1 control is very close to the ground short circuit, Q1 cut off and stop work. On the other hand, after Q83 conduction, the base pole of Q82 obtained a positive bias current, and Q82 continued to conduct, forming a self-locking. As can be seen from the figure, the +5V power supply is fed back to the main 3D printer power circuit board through CN2. If IC6 fails and +5V power supply generates overvoltage, ZD53 will break down the conduction, and Q82, Q83 and Q31 will be conducted through R82 and R83, and Q1 will be cut off to stop the power output.
2. Overcurrent protection
If the load is too heavy or there is a short circuit fault, the fuse F1, F51 may fuse. In case of overcurrent or short circuit, Q1 drain current increases and the voltage of R12 increases, and then R21 is sent to the R pole of IC1 to make Q3 and Q2 conduction and Q1 cut-off, so as to realize overcurrent protection.
3. Other protective circuit
C15 is used to absorb the peak pulse voltage generated by Q1 during the cut-off period to prevent damage to Q1. The function of ZD4 is to clamp the voltage of Q1 control pole to prevent accidental damage of Q1.
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