On the principle of elevator doors brake
In recent years, China's machinery manufacturing and control the level of the elevator has been greatly improved, but unsatisfactory quality door. Elevator door machine set-electromechanical technology as a whole, and the use of frequent, high reliability, quality and performance of the elevator door and operating results directly affect the quality of the entire elevator. Traditional elevator door mechanical parts often used motor gear reducer slowdown after the first, then connect the drive via mechanical linkage car door switch, the mechanical structure of the complex, low transmission efficiency, and adjustment difficulties, high failure rate; way they use a resistor divider control pressure and shunt speed control, high energy consumption not only noisy and poor reliability. Therefore, improving the quality and performance of door has become the consensus of the elevator industry.
When the motor during braking or deceleration, the voltage detection element HL2 detection voltage value, at any time to monitor the value of DC voltage. When the voltage rises to the set value, adjusting the interrupt routine IR1, according reads voltage signals U, calculate the angle β and the associated inverter 8253 timer delay time T a, in order to ensure that the inverter voltage is slightly larger than the line voltage is not the cause of the feedback current is too large; simultaneously open break IR2, detection of the sync pulse interrupt signal IR2, to ensure that the feedback control of the inverter signal synchronized with the grid voltage. Synchronous detection circuit from the power line voltage over the composition of zero-detection and edge detection in two parts, the supply voltage zero crossing interrupt synchronization pulse generated by the external interrupt port 8259 to the 80C196, call the interrupt service routine IR2, 8253 start timer delay, in when the delay time T a end, OUTO 8253 port outputs high level, rising edge strobe 74LS273, corresponding output pulse control signal to open anti-parallel inverter bridge VT11 ~ VT16; next IR1 interrupt again open interrupted IR2, sync pulse detection interrupt signal. So the different pumping voltage to achieve a timed inverter angle β, and synchronized with the grid.
When the motor during braking or deceleration, the voltage detection element HL2 detection voltage value, at any time to monitor the value of DC voltage. When the voltage rises to the set value, adjusting the interrupt routine IR1, according reads voltage signals U, calculate the angle β and the associated inverter 8253 timer delay time T a, in order to ensure that the inverter voltage is slightly larger than the line voltage is not the cause of the feedback current is too large; simultaneously open break IR2, detection of the sync pulse interrupt signal IR2, to ensure that the feedback control of the inverter signal synchronized with the grid voltage. Synchronous detection circuit from the power line voltage over the composition of zero-detection and edge detection in two parts, the supply voltage zero crossing interrupt synchronization pulse generated by the external interrupt port 8259 to the 80C196, call the interrupt service routine IR2, 8253 start timer delay, in when the delay time T a end, OUTO 8253 port outputs high level, rising edge strobe 74LS273, corresponding output pulse control signal to open anti-parallel inverter bridge VT11 ~ VT16; next IR1 interrupt again open interrupted IR2, sync pulse detection interrupt signal. So the different pumping voltage to achieve a timed inverter angle β, and synchronized with the grid.
