Nowadays, lithium battery electric scissors have been widely used in production and life because of their convenience and labor-saving features, such as garden tree pruning, pruning, fruit tree pruning, gardening work, product packaging pruning and industrial production.
Working Principle:
Electric pruning shears are composed of shearing blades, integrated (control) circuits, motor assemblies, deceleration devices and power supplies (lithium batteries). When working, press the controller switch twice to start the brushless motor, and the shearing blade opens and closes 9-12 times per minute through the star-shaped deceleration device to achieve the effect of shearing tree branches and leaves.
However, when using electric scissors, it is easy for the blade of the scissors to perform actions that the user does not intend, for example: the user pulls the trigger, but the blade does not close, or the trigger has returned but the motor is still rotating and the scissors are still working. This will bring safety hazards to the electric scissors or the user.
Technical implementation elements:
Constructing an electric scissors control circuit includes: a central control unit MCU, which is used to receive signals and make instructions; a switch trigger detection circuit, which is connected to the MCU and has a first Hall sensor and a first switch. The first switch is installed at the trigger position of the electric scissors for the user to trigger the motor of the electric scissors in the standby state. The first Hall sensor is connected to the first switch and detects the open and closed state of the first switch, and sends the detected first switch signal to the MCU;
The scissors blade closed position detection circuit is connected to the MCU and has a second Hall sensor and a second switch. The second switch is installed at the blade closed position of the electric scissors. The second Hall sensor is connected to the second switch and detects the open and closed state of the second switch, and sends the detected second switch signal to the MCU;
When the MCU receives the first switch signal as a low level and the second switch signal or the third switch signal is alternately at a high level and a low level, the MCU determines that the electric scissors are working abnormally and issues a forced power-off instruction;
Further, the switch trigger detection circuit also includes a first capacitor, a second capacitor, a first resistor and a second resistor. The first resistor and the second resistor are connected in series, one end of the first capacitor is connected to the first resistor, and the other end is grounded, and one end of the second capacitor is connected to the second resistor, and the other end is grounded. Preferably, the resistance value of the first resistor R1 is 10 kilo-ohms, the resistance value of the second resistor R2 is 1 kilo-ohms, the first capacitor C1 is a 100nf ceramic capacitor, and the second capacitor is a 100nf ceramic capacitor.
Therefore, each detection circuit of the electric scissors control circuit has a corresponding Hall sensor, which can output the corresponding analog signal corresponding to the switch action and the opening and closing position of the scissors blade to the MCU. The MCU can control the rotation of the motor and the movement of the scissors blade according to the corresponding analog signal of the switch action and the opening and closing position of the scissors blade. When the electric scissors are in a state where the trigger is pulled but the scissors blade is stuck, and the trigger is not pulled but the scissors blade is in a working state, the MCU determines that the electric scissors are working abnormally and issues a forced power-off command. This achieves the purpose of reducing the abnormal movement of the electric scissors and providing protection for the electric scissors and users.
Application:
1. Pruning and shaping of nursery gardening flowers.
2. Harvesting fruits in orchards and shearing of rough and hard fruit stalks.
3. Pruning and shaping of municipal garden trees.
4. Pruning and shaping of fruit trees such as grapes, apples, pears, peaches, bayberries, and lychees, and pruning of mulberry branches.
Maintenance:
After using the electric pruning shears for a period of time, the blade needs to be checked. If the blade is worn too much, it needs to be ground on the grinding wheel. When installing, you also need to pay attention to the upper and lower gaps to prevent excessive wear during use.
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