Building Clocks, Belfry Suitable for Schools, Yantai Kexin KX-T-7 Model with Large Gear Ratio and High Torque Core

Kexin Architectural Tower Clock Product Structure:                                                                           

Clock systems are divided into indoor and outdoor sections., indoors, which is further divided into master clock systems and PC monitoring sections.

The outdoor section is the sub-dial, which can be further divided into movements, hands, scales, and lighting systems, etc.

● Principle Introduction

The master clock is equipped with a clock circuit that generates second signals, with an accuracy of0.04 seconds/day, while continuously receiving time signals from the GPS signal station, the CPU corrects 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 and accepts its monitoring. At the same time, the subordinate clock's timekeeping is also monitored by a feedback switch, ensuring that 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 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 govern the entire system's operation.

The master clock features a timing system with precision equivalent to the system's timing accuracy. When the system is powered, the system's timing accuracy is maintained.0.04 seconds/day, the internal timer can maintain operation for over 10 years during power outages.

The master clock controls the timing of the slave clocks. During system installation, it is necessary to adjust the time of the slave clocks 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 tower clock-specific outdoor waterproof cabinet, height is1200mm, equipped with power supply and door lock, front, back, and side panels are all removable, surface treated with washing, phosphatization, and hot galvanizing before powder coating, outer surface meets national standard level 2, inner surface meets national standard level 4, powder coated.The plastic surface is matte, with even coloration. The flatness of the surface does not exceed within a square meter area.1mm, free of wrinkles, cracks, burrs, weld marks, etc. at the surface fold corners; gap between the door and frame less than 1.5mm; all gaps around are waterproof designed; door opens smoothly with no jamming.

●Sub-chime section:

1、Mechanical actuating part：

a、Core appearance: The core shaft is electroplated, and the housing is sprayed with plastic; the core is fully enclosed, oil-free, corrosion-resistant, moisture-proof, shockproof, low noise, low wear, and has a long service life.

b、Movement Structure: Our tower clocks are driven by a constant current chopper method

The motor shaft and worm shaft are rigidly connected, making it easy to ensure the concentricity of the two shafts.

2) The primary stage features a worm gear spoke structure, rapidly 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 traditional connection methods for a compact, rational design, ensuring 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、Timing Monitoring: Add a feedback switch on the movement shaft, introduce another closed-loop control, and continuously feed back the position of the clock hand to the sub-clock.CPU, 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、Drive Circuit: Utilizes a constant current chopper drive method, incorporates closed-loop control to ensure constant current, and guarantees smooth motor operation without stalling, with low power consumption (only 50% of the power consumption of constant voltage drive)(1/6), accurate timekeeping. Principle as follows:

SubclockThe CPU sends control signals to the driver circuit at a frequency of 15 kHz. It latches the driver signal from the CPU at the rising edge of the signal. When the driver signal is low, it activates the driver to move the stepper motor one step. At this point, the feedback resistor in the circuit continuously monitors the current. When it reaches a certain level, the feedback signal activates the feedback loop, shutting off the driver circuit, and the current decreases. When the current drops to a certain level, the feedback loop closes, and the driver loop opens, repeating this cycle to ensure a constant current throughout the driver circuit.

3、Lighting section

a、Lighting Range: 24 hoursLighting can be set at any time within 24 hours; the factory default is from 5 PM to 6 AM the following morning.

b、Luminescent Body: During external illumination, the luminescent body is used with a diameter of5mm LEDs 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; when used for internal lighting, the light source employs Philips cool light tubes, providing soft and even illumination suitable for continuous use for several years.

c、Lighting Power Supply: For24V AC power supply.