Electronic Clock II - Generating the Clock Signal pt. 2

Posted on Sat 16 June 2018 in Electronics

In the previous post, we saw how to make a 2Hz clock signal. However, for the seconds counter, we will need a 1Hz clock signal. In order to achieve this, I will clock down the frequency using a JK Flip Flop:

Flip-Flop: Concept

A Flip flop is a one-bit storage device which looks somewhat like this:

flip flop

The truth table of this device looks somewhat like this:

truth table

Note that the flip flop toggles only on the rising edge of the clock. Therefore, in order to clock down the frequency by 2, we need to set the J and K bits high and feed the clock signal in to the CLK pin, thereby obtaining a 1Hz signal on the Q pin.

Adding the flip-flop to our circuit:

On adding the flip flop to our circuit, the schematic looks somewhat like this (The 4060 has been carried over from the previous post):

1hz schematic

As calculated, this gives us a frequency of 1 Hz on the Q pin

oscilloscope output

This concludes our clock signal source. In the next post, we will have a look at counting seconds with the clock signal.

- Deb