Wednesday, September 3, 2014
Build a Toggle Touch Switch Using Two Inverter Gates
We can make a simple touch switch using only two inverter gates, two resistors, and two capacitors. The schematic diagram of the schema is shown in the figure below. At power up, the output (of U1A) will be high, and the inverting output will be low because U1A gate will be triggered to ground level by C2. After triggered, the low level of U1A input is maintained by U1B output via R2.
Toggle Touch Switch Using Two Inverter Gates Circuit Diagram
After U1A input goes high then U1A output will go low, and now U1B will go high to maintain high voltage level of U1A via R2, so we can release our finger without loosing the last state. Touching the pad again after we release our previous touching will toggle the output as the condition is reversed.
After we touch the pad, we have to release before 1 second (R2C2 time constant) elapsed. If we touch the pad longer than R2C2 time constant then the output will oscillate (about 1 Hz).
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment