So the main reason inductors aren't used in debouncing is because they can drive too much current into sensitive electronics thus damaging them. Instead capacitors are used normally to smooth out the signal. But I came up with this design that uses an inductor. Thoughts?

 

Switch bounce has been solved in many different ways without using inductors.

 

Switch bounce has been solved in many different ways without using inductors.

Thank you for letting me know. I never would have guessed.

 

I did not intend to brush aside your suggestion.

Note that in this RC circuit, the elements are on the input side of the gate forming a low pass filter.

 

I don’t see how your circuit does anything to debounce. When the switch bounces to open, the input jumps back to high immediately.

 

But I came up with this design that uses an inductor. Thoughts?

Certainly in theory you could design a switch debouncer circuit using an inductor instead of a capacitor, but there's no practical reason to use such a circuit, since inductors are much more expensive and less ideal than capacitors.

 

Here is a simulation of your circuit. The MOSFET simulates a bouncy switch that is switched on at 10ms then bounces off for 5ms then back on. I see no evidence of any debouncing action.

 

Instead capacitors are used normally to smooth out the signal. But I came up with this design that uses an inductor. Thoughts?

If anything, an inductor is the inverse of a capacitor. You can't just pull out a cap and put in an inductor.
The RC makes a low pass filter. If you are using an inductor you need to make a low pass filter using RL. Very different circuit.

 

inductors are high impedance for HF signals so circuit posted by TS will obviously not work as debouncer.
so yeah, different circuit with inductor would be needed,

 

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So the main reason inductors aren't used in debouncing is because they can drive too much current into sensitive electronics thus damaging them. Instead capacitors are used normally to smooth out the signal. But I came up with this design that uses an inductor. Thoughts?

I fail to see how the circuit you have drawn debounces the switch.

Care to explain?

 

or why would debounce be used as a form of circuit protection. every debounce i ever used was there to clean the signal and prevent ringing near edges.

 

I fail to see how the circuit you have drawn debounces the switch.

Care to explain?

It doesn’t, see my simulation in post #7

 

pretty sure he is aware of it, his comment was addressing TS, asking him to explain how is this supposed to work according to him

 

This circuit bounces even worst than pure resistor.

Consider after pressing button the inductor is a bit charged. Once the button is open for a while because of contact breaking the schmitt input is pushed to -0.7V so schmitt flips. Then after making a contact again the schmitt flips back. So it causes no debouncing at all.

Also 3m7 inductor together with 220 makes time constant about 17us. The button bouncing last about few msec. So you would need a very big inductor like 1H.

 

All the debouncers I'm aware of suppress (or avoid the effects of) voltage changes. Perhaps a modification of the TS's circuit could use the inductor to suppress current changes?

 

The concept of the RC debounce scheme is to avoid multiple voltage changes past the input device threshold. An adequate RC network does that. AND, as mentioned already, the inductor plus diode adds an extra part that is polarity sensitive. What would be the intended benefit provided by the inductor plus diode scheme? OR is this an exercise to evaluate an idea??

AND, since a button is normally operated by a human, intentional multiple operations are also possible.

In all cases, the safest scheme is to set a bit that is eventually reset when the input is acknowledged.
That is possible in both hardware and software, systems. A set bit does not care or notice if it is set a second or multiple times.
In my career I have only seen one individual who could operate a keypad fast enough to confuse the well designed debounce scheme. That problem was solved by asking the lady to slow down a bit for our machine.