Kexin Architectural Tower Clock Product Structure:
The clock system is divided into indoor and outdoor sections., the interior is further divided into master clock systems and PC monitoring sections.
The outdoor section consists of the sub-dial, which is further divided into the movement, hands, numerals, lighting system, and so on.
● Principle Introduction
The master clock features a clock circuit that generates 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.At 15 seconds, the output drive signal activates the motor, completing the timing operation.
The subordinate clock transmits its status back to the master clock, accepting its monitoring. Simultaneously, the subordinate clock's timekeeping is also monitored by feedback switches, ensuring the entire subordinate clock forms a closed-loop system. Furthermore, the master clock and subordinate clock together form a larger closed-loop system, thereby guaranteeing the entire system's accuracy.
● Master Clock Section:
a）Control System: The master clock serves as the control center of the system, issuing various control commands and signals from the master clock to regulate the overall operation of the system.
The master clock is part of the clock system, with timekeeping accuracy matching that of the system. When the system is powered, the system's timekeeping accuracy is0.04 seconds/day, the system's internal timer can maintain operation 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 must 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 from 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 uses a tower clock specialty outdoor waterproof cabinet, height is1200mm, equipped with power supply and door lock, front, back, and side panels are all removable, surface treated with washing, phosphatizing, and hot-dip galvanizing before powder coating, exterior surface meets national standard grade 2, interior surface meets national standard grade 4. Powder coatingThe surface is textured with a matte finish and even coloring. The flatness of the surface does not exceed within an area of 1 square meter.1mm, free of wrinkles, cracks, burrs, welds, and other marks at the surface creases; the gap between the door and frame is less than 1.5mm; all gaps around are waterproof designed; the door opens smoothly without any jamming.
●Sub-Clock Section:
1、Mechanical Actuating Section：
a、Core Appearance: The core shaft is electroplated, and the casing is plastic coated; the core is fully enclosed, oil-free, corrosion-resistant, moisture-proof, shockproof, low noise, low wear, and has a long service life.
b、Mechanical Construction: Our tower clocks are powered by a constant current chopper drive method.
The motor shaft and worm shaft are rigidly connected, making it easy to ensure the concentricity of the two shafts.
2) The primary gear features a worm and 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 quality assurance easier.
3) Revolutionize traditional connection methods for a compact, rational design that ensures core operation reliability.
4) This core is particularly well-suited for constant current chopper circuit designs, ideal for constant current chopper drive methods.
2、Electrical Control Section:
a、Time Signal: Strike ClockThe 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、Movement Monitoring: Add a feedback switch to the movement shaft, introduce another closed-loop control, and constantly feedback the position of the hour hand to the sub-dialCPU, the sub-clock CPU compares the feedback signal from the feedback switch (actual running position) with the timing time stored internally (theoretical running position), thereby adjusting the position of the clock hand in real-time to ensure accurate timekeeping.
c、Driver Circuit: Utilizes a constant current chopping drive method, incorporates closed-loop control to ensure constant current, and guarantees smooth motor operation without stalling, with low power consumption (only 1/3 of constant voltage drive power)(1/6), Timekeeping accuracy. 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, turns on the drive when the drive signal is low, causing the stepper motor to move one step. Meanwhile, the feedback resistor in the circuit constantly monitors the current. Once it reaches a certain level, the feedback signal activates the feedback loop, cutting off the drive circuit, and the current drops. 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、Luminous section
a、Lighting Area: 24 hoursLighting can be set at any time within 24 hours; factory default is from 5 PM to 6 AM the next morning.
b、Luminescent Body: During external illumination, the luminescent body employs a diameter of5mm LED, available in red, green, and yellow colors, with a typical brightness of 600mcd, wavelengths at 640nm for red and 525nm for green, and a lifespan exceeding 100,000 hours; during internal lighting, the light source uses Philips cool light tubes, providing soft and even illumination, suitable for continuous lighting for several years.
c、Lighting Power Supply: For24V AC power supply.
