Push button 4027

Thread Starter

newbielectronics

Joined Aug 29, 2006
1
Hi,
I am new to electronics and I was wondering if you could tell me how to use a 4027 JK flip flop to create a simple on off toggle switch with a push button. I was also wondering how you know which pins to wire and what each pins function is. I know there is a datasheet but I still don't know what Q and related mean how to use them and what value of capacitors and resistors I need around the circuit. How do you figure all this out?
Thanks.
 

pebe

Joined Oct 11, 2004
626
Hi,
I am new to electronics and I was wondering if you could tell me how to use a 4027 JK flip flop to create a simple on off toggle switch with a push button. I was also wondering how you know which pins to wire and what each pins function is. I know there is a datasheet but I still don't know what Q and related mean how to use them and what value of capacitors and resistors I need around the circuit. How do you figure all this out?
Thanks.
This link may help you understand the JK flip flop.

http://www.allaboutcircuits.com/vol_4/chpt_10/6.html/j_k_flip_flops
 

lightingman

Joined Apr 19, 2007
374
Does it have to be a 4027 ?

It is very easy to do it with a 4013.

Input to clock (with pull down resistor of about 10K), tie data input to inverted Q output, tie reset and set to logic "0".

Now if you are using a switch, you should be aware of switch bounce problems I.E. the noise caused by the switch contacts when they come together or move apart.

There are a few ways of overcoming this, but try this one:-

Connect one end of the switch to VCC, the other end to a resistor (10K) to GND.
From the junction of the switch and resistor connect a capacitor with the other end of the capacitor (10nF) through another 10K resistor to ground.
At the junction of the capacitor and resistor, connect a diode "anode" (1N4148, 1N916), and then the cathode to the clock and pull-down resistor on the 4013.

If the switch is very bad, it may help if you put a small capacitor accross it (about 470nF)

Daniel.
 
Top