Abstract: An identity certificate may be issued to a blockchain node. The issuance may include issuing a first identity certificate to a first terminal and receiving a second identity certificate issuance request that is from the first terminal. A second identity certificate may be issued to the first terminal, and a third identity certificate issuance request is received from the second terminal. A third identity certificate is issued to the second terminal, so that the second terminal forwards the third identity certificate to the third terminal.

Abstract: A soldering assistance device is used for soldering a multi-pin electronic element with a row of pins on a PCB. The row of pins includes an outer pin at two ends thereof. The soldering assistance device includes a holding portion and a soldering portion connected to the holding portion. The soldering portion is adjacent to the outer pin. An interval between the soldering portion and the outer pin is less than an interval between each two adjacent pins of the row of pins. The soldering portion is made of a metal which is easy to solder. A soldering method using the soldering assistance device is also provided.

Abstract: A window covering driving device includes a motor and a control circuit, the control circuit is provided with a microprocessor, a control wire, a control signal input terminal, and a switching circuit and the motor is connected to a drive power supply via the switching circuit. The switching circuit is connected to the microprocessor and the control signal input terminal is connected to the microprocessor via the control wire. A safety position limiting wire is also included with one end of the safety position limiting wire being connected to the microprocessor and the other end is connected to a safety position limiting signal control terminal. The safety position limiting wire and safety position limiting signal control terminal are attached so that, when the safety position limiting signal control terminal is at the position limiting state, as the motor runs to the position limiting position, it will automatically stop.

Abstract: The present invention discloses a window covering driving device that comprises a motor and a control circuit; the control circuit is provided with a microprocessor, a control wire, a control signal input terminal, and a switching circuit; the motor is connected to a drive power supply via the switching circuit; the switching circuit is connected to the microprocessor; the control signal input terminal is connected to the microprocessor via the control wire; wherein, it also comprises a safety position limiting wire; one end of the safety position limiting wire is connected to the microprocessor, and the other end is connected to a safety position limiting signal control terminal.