Digital Electronic Clock LM8560 Graduation Project

Hello! The LM8560 is a typical digital clock circuit, which is very functional except that it does not have a 60Hz oscillator itself.

It can be directly replaced with TMS3450, LM8360 is an application circuit that used to be used by a professional state-owned factory in China to make digital clocks and timing radios. It has stable performance, time function, timing function and sleep function. Ability to use 50 or 60Hz frequencies as the reference frequency for digital clocks.

The following is an application circuit that can be powered by AC and DC is provided above. As the key to DC power supply, a high-precision reference frequency is required, and a 32768Hz inexpensive crystal and CD4060 digital circuit are used to form a circuit that can provide a 60Hz reference frequency. It is important to note that:

The special display screen of the integrated circuit belongs to the type of double cathode power supply, which is special and cannot be used with the screen of other circuits, so it is necessary to ensure that their driving waveform is very symmetrical. Here, a CD4013 circuit is used for inverting, and two C9013s take turns to supply power to the two cathodes of the screen. At the same time, in order to save the power of the battery, a triode C9013 automatically cuts off the power supply of the display screen, and realizes the automatic blanking when the AC power is off.

Features: LM8560 integrated circuit contains display decoding driver circuit, 12 24 hours selection circuit and other setting warning circuits.

It has a wide operating voltage range (7 5-14V) and operating temperature range (20C-+70C). Its own power consumption is very small, and the output can directly drive light-emitting diodes or LED digital displays.

This is the circuit diagram of the LM8560 AC positive power supply

TMS1943, TMS3450 and LM8560 are all representative varieties of LED digital clock driver ICs.

All three circuits can meet your three requirements.

The reference clock frequency of the above three circuits adopts the power frequency alternating current 50 or 60Hz frequency as the reference, and the timing accuracy is determined by the frequency of the local power grid. In the 90s of the 20th century, these chips are difficult to meet people's requirements for accuracy due to the lack of accuracy of AC grid frequency, and the error is relatively large compared with quartz clocks, and can not be separated from the AC power grid, and gradually abandoned by people.

However, it is possible to design a precision 60Hz time-based frequency generation circuit to meet the requirements of very accurate timing.

This circuit is sold online, including integrated circuits, time-based generators, LED displays, a total of about 13 yuan, because I am not a seller, so I do not advertise.

There are many functional circuits to realize the electronic clock, which are made by single-chip microcomputers, digital circuits, and special chips.

The special chip is relatively simple to do, and the stability and reliability are also high. For example, LM8560 and CS8560 chips can be realized. As long as CD4060 and crystal oscillator are added to the periphery, it can work with 60Hz oscillation signal, and of course, there is also an LED clock screen.

The circuit is simple, but it also requires some basic knowledge.

Typical application circuit diagram of the LM8560 integrated circuit.

This is the simplest digital clock circuit, and it can also be replaced with multiple LEDs for digital tubes

It couldn't be simpler than ever.

An 8 requires 9 LEDs to display the time, at least the clock and minutes.

That's 4 numbers.

How many LEDs are you going to use?

You're going to have to use other chips.

I recommend that you use a digital tube or an LCD screen.

If you want to make it simple, use a microcontroller to program.

LCD screen display.

If you are troublesome, you can use a dedicated integrated circuit, such as LM8560, to directly refer to the standard connection of the corresponding PDF file.

Or you can use a single-chip microcomputer and a few peripheral ICs to do it, there are many ways to implement it, and the program has to be written by yourself.

The simplest I've ever done is a single-chip microcomputer +1302 chip, the hardware circuit is very simple, you just have to write your own program, ** someone has done it. You can search for large-size digital tube drivers Someone specializes in circuits, and you can just connect your own LEDs when you go back.

Is it a time display circuit, if it is composed of LM8560 CD4060 integrated circuit, crystal oscillator, LED clock screen, etc.!