Kexin Architectural Tower Clock Product Structure: Clock systems are divided into indoor and outdoor sections., the interior is further divided into master clock systems and PC monitoring sections.The outdoor section is the sub-dial component, which can be further divided into the movement, hands, scales, and lighting system, etc.
● Introduction to PrincipleThe master clock has its own clock circuit, generating second signals, with an accuracy of0.04 seconds/day, while the CPU continuously receives time signals from the GPS signal station, correcting its own time signals to ensure accuracy.The master clock continuously sends time signals to the slave clocks, and the slave clocks accumulate time as they receive.At 15 seconds, the output drive signal powers the motor, completing the timing operation.The subordinate clock feeds back its status to the master clock, accepting its monitoring. At the same time, the subordinate clock's timekeeping is also monitored by feedback switches, ensuring the entire subordinate clock forms a closed-loop system. The master clock and subordinate clock together constitute a larger closed-loop system, thereby guaranteeing the overall accuracy of the system.
● Master Clock Section:a）Control System: The master clock is the control center of the system, issuing various control commands and signals from the master clock to govern the entire system's operation.The master clock features a clock system with timing accuracy equivalent to the system's accuracy. When the system is powered, the timing accuracy of the system is maintained.0.04 seconds/day, the internal timer of the system can maintain for over 10 years during power failure.The master clock controls the running time of the slave clocks. During system installation, the time of the slave clocks needs to be adjusted on the master clock.The CPU determines whether the subordinate clocks are running normally, speeding up forward, or speeding up backward based on the time of the subordinate and master clocks. If the system loses power at any time, the master clock can remember the time of each subordinate clock. Upon the next system power-up, the master clock continues to run based on the remembered subordinate clock times. The main control cabinet requires 9 wires to control the running of each subordinate clock, with 6 wires being motor drive lines and 3 being core feedback lines.b）Cabinet: The master clock is housed in a specialized outdoor waterproof cabinet designed for tower clocks, measuring 1200mm in height. It is equipped with power supply and a door lock. The front, back, and side panels are removable. The surface undergoes washing, phosphatization, and hot galvanizing treatments before being spray-painted, with the outer surface meeting national standard Grade 2 and the inner surface meeting national standard Grade 4. SprayThe surface is matte and evenly colored. The flatness of the surface does not exceed 1mm within an area of 1 square meter. There are no wrinkles, cracks, burrs, weld marks, etc. at the folding corners. The gap between the door and the frame is less than 1.5mm. All gaps around are designed for waterproofing, and the door opens smoothly without any jamming.
●Sub-dial section:
1、Mechanical Actuator Section：a、Core Appearance: The core shaft is treated with galvanizing, and the casing is electrostatically coated; the core is fully enclosed, requiring no oil changes, and is corrosion, moisture, shock, and noise-resistant with minimal wear and extended lifespan.b、Movement Construction: Our tower clocks are driven by a constant current chopper methodThe motor shaft and worm shaft are rigidly connected, making it easy to ensure the concentricity of the two shafts.2) The primary stage utilizes a worm gear spoke structure, quickly reducing the transmission ratio. The design is simpler and more compact, transforming the originally complex core variable speed structure into a very simple miniature reducer, making it easier to ensure quality.3) Revolutionize the traditional connection method for a compact and rational design, ensuring the movement operates reliably.4) This core is particularly well-suited for constant current chopper circuit design, ideal for driving constant current chopper circuits.
2、Electrical Control Section:a、Time Signal: The subordinate clock CPU (AT89C51) receives the standard time signal from the master clock once per second, then compares it with its own running time to determine its operation (normal running, chasing, reversing, waiting).b、Timing Monitoring: Adds a feedback switch on the movement shaft, introducing another closed-loop control. It continuously feeds back the position of the clock hand to the sub-clock CPU. The sub-clock CPU compares this feedback signal (actual timing position) with its internal memory of timing time (theoretical timing position) to adjust the position of the clock hand in real-time, ensuring accurate timing.c、Drive Circuit: Utilizes a constant current chopper drive method, incorporates closed-loop control to ensure constant current, and guarantees the motor runs smoothly without stepping, with low power consumption (only 1/6 of constant voltage drive power), and accurate timing. Principle as follows:SubclockThe CPU sends control signals to the drive circuit at a frequency of 15KHz. It latches the drive signal from the CPU on the rising edge of the signal. When the drive signal is low, it activates the drive to move the stepper motor one step. At this point, the feedback resistor in the circuit constantly monitors the current. Once it reaches a certain level, the feedback signal opens the feedback loop, cutting off the drive circuit, causing the current to drop. When the current falls to a certain level, the feedback loop closes and the drive loop opens, repeating this cycle to ensure a constant current throughout the drive circuit.
3、Lighting sectiona、Lighting Period: Lighting can be set at any time within a 24-hour period, with the default setting at 5 PM to 6 AM the following morning upon factory shipment.
b、Luminescent body: During external illumination, the luminescent body employs a diameter of5mm LEDs in red, green, and yellow colors, with a typical luminous intensity of 600mcd and a wavelength of 640nm red/525nm green, lifespan over 100,000 hours; during indoor lighting, the light source utilizes Philips cool light tubes for soft and even illumination, ensuring years of continuous lighting.
c、Lighting Power Supply: For24V AC power supply.
Engineering Real Shots:
