Sewing Machine With Three Phase AC Motor Missing Indication Device

In garment production, industrial sewing machines are generally equipped with 380 volt and 370 watt small power three-phase AC motors. Due to overload or a phase fuse burning, the damage often occurs due to the lack of phase, which will cause some economic losses and cause fire hazards.

The author made a sewing machine.

Lack of phase indicating device, the three-phase AC motor phase missing indicating device has filled up the motor phase missing protection device on the market, which is not suitable for the blank of the small power motor. The device has the advantages of simple structure, low cost, high reliability and obvious indication, and can be widely used in garment production enterprises.

1, circuit principle

The device can be installed in the machine's eye - catching position, using red, green and blue high brightness LED light emitting diodes to display the real-time state of the three-phase AC power supply.

When one of the AC power sources is disconnected, the high brightness LED LED with the corresponding color will be extinguished. At this point, the operator will turn off the power switch of the sewing machine in time for overhaul, thereby preventing the motor from being damaged.

The schematic diagram of the circuit is shown in Figure 2. A, B and C are 380 volt three-phase AC power supply, which is connected to the front end of the power switch, K is sewing machine power switch, M is sewing machine three-phase alternating current motor, D1, D2 and D3 are red, green and blue high brightness LED respectively. R1, R2 and R3 are partial voltage resistance, of which, 90 thousand and 90 thousand watts are resistors.

2, circuit board production

The production of circuit boards, D1, D2 and D3 are evenly distributed in the central part of the circuit board, and each phase of the A, B and C phases are monitored respectively.

The size of the circuit board can be designed to be 4 centimeters and 8 centimeters. Other components are distributed evenly over the top of the circuit board: D4, d5 and D6; R1, R2 and R3 are evenly distributed under the bottom of the circuit board; G is the ground wire access point, which can be connected by one wire; a, B and C are the three phase AC access points of the rear end of the power switch of the sewing machine; O1, C, and D6 are fixed by small screws.

The small black spots are small circular holes, which are used for inserting pins of the electronic components, and the pins of the relevant components are connected by welding wires.

this

The shell can be made of insulating plastics of 5 cm x 10 cm * 2 cm, and the three color high brightness LED light emitting diodes are evenly distributed in the central position of the front of the shell, indicating obvious and easy to identify.

The power cord is introduced from the lower right side of the housing, making it relatively simple.

3, installation

The device is simple in installation and generally installed in the central part of the sewing machine's head. When it is installed, it will access 380 volt three-phase AC power from the rear end of the sewing machine power switch.

For example, the heavy machine ddl8700 high-speed lockstitch sewing machine can use M4 screw to fix the device in the process hole at the center above the machine head, so that the operator can find abnormal conditions in time, and quickly take power off and shutdown measures to prevent accidents such as burning motor.

In the general sewing shop of large and medium-sized garment manufacturing enterprises, due to the large noise,

It is difficult to identify the fault sound after the motor is out of phase, which is worth popularizing and using.

Interested friends may wish to have a try.