ecSwitch is an easy and convenient way to add a switch to your prototyping projects, it includes a debouncing circuit based on a Schmitt trigger which makes it a perfect fit for microcontrollers and digital circuits.
The supply pins: V+ will be connected to an input voltage between 1.65 and 5.5 Vdc and G- to ground or 0 Vdc. Warning! If the connections were swapped around the integrated circuit would be damaged.
The output pin (marked as “out” on the board) needs connecting to the microcontroller or digital circuit input, this pin exhibits a low voltage level (close to 0 Vdc) if the switch is released and similarly a high voltage state (value close to V+) when it is pushed down.
The output pin can either source or sink a maximum current of 50 mA, the recommended electrical values can be found on its datasheet which is linked at the bottom of this page.
The ecSwitch schematic is as shown in the drawing:
A momentary switch and debouncing circuit composed of: R1, R3, C1 and an integrated circuit (Schmitt trigger). C2 is a decoupling capacitor placed between the supply pins of the Schmitt trigger.
The output of the debouncing circuit remains steady until a few milliseconds after the button press happens, this delay avoids a bouncing of the output levels (high frequency oscillation between opened and closed states) which may occur otherwise. If not considered, a single press could be detected as multiple becoming a problem source for the circuitry connected to the switch.
The image below shows the result of pressing and releasing the momentary switch, a probe is connect right close to R1 and R3 (yellow signal) and other to the output pin (blue signal).
The debouncing circuit ouput remains unchanged for 15-18 ms right after the buttons is pressed, cancelling the transitory bouncing for the fist milliseconds everytime the switch opens or closes.
- Dimenisions: 9.5 mm x 16.8 mm.
- Input voltage: 1.65 – 5.5 Vdc.
- Maximum output current: 50 mA (Check recommended values in datasheet).
The board includes a momentary switch and all the required components to have a debouncing circuit in a small sized board ready to fit into a bread board.
ecSwitch can be purchased from our shop at tindie: