Features:
1. The circuit board used in this digital clock kit is a standard FR-4 epoxy fiber board, and the circuit boards are double-sided plated with antioxidant green oil, which shows more class and excellent quality.
2. The control chip adopts AT89C2051, and the digital tube adopts 3 two-bit red co-positive LED digital tubes, with clear display and high brightness;
3.S1 button is used to calibrate the time, press and hold for more than 2 seconds to enter the calibration time state and exit, fast touch for adjusting the time value;
4. This circuit adds a 3V battery backup, power outage AT89C2051 with battery backup power supply, the clock will not stop, but the digital tube does not display;
5. This kit is already very mature kit, pads are all done spray tin treatment, easy to weld, directly in accordance with the drawings can be installed successfully, the program has been handcuffed to the inside of the microcontroller, plugged in can be used, accurate time.

Product parameters:
Supply voltage:DC5--12V
Recommended voltage: DC 9V
Operating current: 35mA (external power supply, self-provided)
Standby current: 1.2 mA (backup battery power supply)
Board size:90MM*70MM

Product Description:
1, 89C2051 digital clock kit, the control chip using AT89C2051, digital tube using three two-bit red co-positive LED digital tubes, display clear high brightness, because the scanning display, so each digital tube abcdefg each pin using a bus in parallel, change the resistance value of R4-R10 can change the display brightness.
2, S1 button is used to calibrate the time, press and hold for more than 2 seconds to enter the calibration time state and exit, a quick tap is used to adjust the time value.
3, this circuit adds another 3V backup battery, when the power failure AT89C2051 uses the backup battery power supply, the clock will not stop, but the digital tube does not display, after the incoming call the backup battery loses its role, AT89C2051 uses the external power supply, the digital tube displays normally. So you can add a power switch, turn off the power when you go out, and then hit it when you come back and display normally, to achieve the
The purpose of saving electricity.
4、Accurate timekeeping.
5, this kit is already very mature kit, directly in accordance with the drawings can be installed successfully, the program is also handcuffed to the microcontroller inside, plug it in to use, the installation of the kit requires a certain degree of electronic basis.
6, this kit is very suitable for vocational schools, colleges and universities teaching experiments, and high utility, successful installation can be used.

Precautions:
1. There are three jumper wires in the circuit, directly with the wire or component pins can be shorted
2. Pay attention to the details of the long and short legs and holes during installation.
3. Pay attention to the installation direction of the switch
4. Pay attention to distinguish between long and short legs of small electronic components and positive and negative poles, as well as the holes of the motherboard
5. Pay attention to the black side of the installation of the white side of the black pole negative pole

Product list:
1 X clock kit loose