Flip-Flop Debouncer Switch

Posted on Jan 22, 2013

Although this circuit uses a 74HC74, any CMOS variant of this flip-flop will work. IC1A acts as a true/ compleme

Flip-Flop Debouncer Switch
Click here to download the full size of the above Circuit.

nt buffer. RI and R2 ensure that IC1A comes out of reset before the clock"s edge occurs. R3 applies IClA"s logic state to pins 1 and 3. When the switch closes, the next logic state stored on the capacitor transfers to the flip-flop"s reset and clock inputs. Releasing the switch lets the capacitor charge to the next state via R4. IClA"s output is the LSB; IClB"s output is the MSB. Notice that the counter"s state advances when the switch is first pressed, rather than when it"s released; the latter is the case with many other switch-debouncing schemes. You can replace RI with a 22-pF capacitor to reduce the circuit"s sensitivity to parasitic effects. The addition of this capacitor also lets you lower the magnitude of R2 and R3 by a factor of 10.

Leave Comment

characters left:

New Circuits



Popular Circuits

PIC Programmer
12V lead acid battery charger by LM317K
Voltage-controlled cipher scheme of constant-current source of output high-power of bipolar
color sensor circuit diagram
car battery charger schematics
Schematic Diagram Schema HO Train Model Lighthouse Flasher
building my own aux circuit car stereo feedback