Reference Manual for 4-Bit IN-12 Clock Production
Notes in the Production Process
Tools required for production include a constant temperature electric soldering iron, soldering tin, vice, pointed nose pliers, diagonal pliers, tweezers, small slotted screwdriver, art knife, ruler, AB glue, marking pen, multimeter, and flux.
The clock is powered by a 12V/1A power supply. A supply below 12V will prevent the IN12 glow tubes from displaying. Avoid unstable power supplies, such as those from computer hosts.
Copper wire should be cut short before use and straightened by clamping at both ends with pliers.
The production sequence involves assembling the Booster power supply section, 5V voltage section, Button section, Clock section, Glow tube surrounding scaffolding, Neon circuit, Base processing, Power interface, and finally, Combination.
Safety Warning: After powering on, the circuit contains high voltage. Do not touch high-voltage parts. Debugging and use should be done with a glass cover. Exercise special caution if you are carrying medical electronic devices.
Method for Setting Button Time
- Press the SET key once. The hour ten digit will flash. Use the plus or minus keys to adjust it.
- Press SET again. The hour digits will flash. Adjust using plus or minus keys.
- Press SET again. The minute ten digit will flash. Adjust using plus or minus keys.
- Press SET again. The minute digits will flash. Adjust using plus or minus keys.
- Press the SET button again to save. The display will then work normally.
Remote Control Time Setting: Press the 'C' key. The hour ten digit will flash. Adjust the hour ten digit, hour one digit, minute ten digit, and minute one digit numbers sequentially.
Production Steps
1. Booster Power Supply Part
This module inputs 12V and outputs 170V (range 168V-180V). Ensure safety during operation. The output voltage can be adjusted using the ADJ (3239W) adjustable resistor if incorrect.
Components Used:
- Resistors: 1K, 2.2K, 470K, 22K, R025J (5W)
- Capacitors: 400V/4.7uF, 0.0022uF, 35V/330uF
- Diodes: BYV26E, IN4148
- Transistors: 7N60C, 8550
- ICs: MC34063API (U1), DIP8P
- Inductor: 221
- Potentiometer: 3296W
Visual Description: The circuit diagram shows a boost converter using the MC34063 IC to step up the voltage. The actual welding surface images display the physical assembly of these components on a wire frame, demonstrating a point-to-point wiring technique.
2. 5V Power Module, Button Module, Remote Control Module, Battery Module
This section covers modules that provide 5V (VCC) and 3V (VCC2) from a 12V input.
Components Used:
- Voltage Regulators: L7805CV, LM78H05K
- Microcontroller: STC15W408AS
- Clock Chip: DS1302Z
- Crystal: 32.768KHZ
- Buttons
- Battery: CR2032
- Resistors: 10k
- Capacitors: 16V/100uF (x2), 104 (0.1uF)
- Diode: SL0038LS
Visual Description: Images show the individual components, including the voltage regulators, microcontroller (STC15W408AS) and clock chip (DS1302Z) in DIP packages, the CR2032 battery, buttons, and crystal. Circuit diagrams illustrate the connections for these modules, including power regulation and interfacing with the microcontroller. The assembled button module shows several tactile switches connected to a small board.
Voltage Regulator Details:
- VCC voltage is 5V, with VCC current being smaller than VCC2. The two cannot be mixed during welding.
- The metal three-terminal voltage regulator (LM78H05K) is asymmetric with differentiated pins. The voltage of VCC2 is 5V, and its current is greater than that of VCC.
3. Clock Chip
Troubleshooting: If the clock does not run on time, 20pF capacitors can be added to pins 2, 3, and 4 of the clock chip (with the other pin of the capacitor grounded).
Connection: Connect the clock chip and the MPU. Add a 10K pull-up resistor to pins 6 and 7 of the clock chip.
Visual Description: Images show the clock chip (DS1302Z) connected to the crystal and buttons via wires. A separate image shows the microcontroller (STC15W408AS) and clock chip mounted on a wire frame assembly.
4. Drive Part
This section details the components and circuit for driving the display elements.
Components Used:
- Ceramic Capacitors: 104/475 (0.1uF)
- Integrated Circuits: K155ID1 (Russian equivalent of SN74154 or similar logic gate), 74HC595N (Shift Register)
Visual Description: Images display the K155ID1 and 74HC595N ICs. Circuit diagrams show how multiple shift registers and logic ICs are interconnected to drive the display segments. The assembled driver modules show these ICs wired together on a frame.
5. Neon Lamp Part
Neon lamps and resistors are not polarized.
Components Used:
- Neon Lamps
- Resistors: 200K (x2), 510R, 10K
- Transistor: 13005N
Visual Description: Images show the neon lamps, resistors, and the 13005N transistor. The circuit diagram illustrates a neon lamp driver circuit using a transistor. Assembled images show neon lamps wired with resistors and a transistor.
6. IN12 Glow Tube Part
Components Used:
- IN12 Glow Tubes (x4)
- Resistors: 20K (x4)
- Copper Pillars
IN12 Glow Tube Pin Definition:
Visual Description: Images show the IN12 glow tubes and resistors. A close-up of an IN12 tube shows its 12 pins, with pin 11 typically connected to 170V. A diagram illustrates the pin layout and numbering for the IN12 tubes. The circuit diagram shows how the IN12 tubes are connected to the driver modules via resistors for displaying digits (ONES, MIN, TENS, HOUR). Assembled images show the IN12 tubes mounted on copper pillars.
7. Combination of IN12 Glow Tube and Driver Module
This section details the integration of the IN12 glow tubes with the driver circuitry, typically involving shift registers (74HC595N) and logic ICs (K155ID1) to control which digit and segment is activated.
Visual Description: Circuit diagrams show the complex interconnections between the microcontroller, shift registers, logic ICs, and the IN12 glow tubes. Images display the physical assembly of these combined modules.
8. Base Part Combination
This section shows the overall combination of the various modules onto the base structure, integrating the booster power supply, clock chip, buttons, and other modules.
Visual Description: A combined circuit diagram illustrates how all the sub-circuits are interconnected. Images show the partially assembled clock on its base.
9. Combine All into a Complete Product
Assembly Notes:
- Connect the buttons to pins 1, 26, 27, and 28 of the MPU chip (STC15W408AS).
- Connect VCC-5V to pin 12 of the MPU chip and pin 1 of the clock chip (DS1302Z).
- Connect the external 12V power supply to the 12V+GND input.
Enhancement: Adding 104 capacitors (0.1uF) to the MPU power supply pins can enhance stability.
Visual Description: Images show the final assembly stages, with all modules connected and mounted. The complete product is shown under a glass dome, with the IN12 tubes displaying digits.
