Shorting a small capacitor with a switch

[Pimpom]

I know it's not a good idea to short-circuit a charged
capacitor, especially a large electrolytic. What about
smaller caps - like a low voltage ceramic disc of 0.1uF or
less? And if the shorting element is a low-power switch like
one of those ubiquitous little square tactile microswitches,
is the discharge energy enough to erode the contacts and
shorten its life significantly?

If it helps evaluate the situation, take as an example two
cross-coupled NAND gates in the classic toggle switch
configuration. As a bias to determine the initial state, say
one input of one NAND element has the small cap to ground
and is tied to Vdd via a resistor of ~100k. The microswitch
parallels the capacitor. Is it advisable to insert a series
resistor to limit the discharge current?

 

[Jamie]

I know it's not a good idea to short-circuit a charged
capacitor, especially a large electrolytic. What about
smaller caps - like a low voltage ceramic disc of 0.1uF or
less? And if the shorting element is a low-power switch like
one of those ubiquitous little square tactile microswitches,
is the discharge energy enough to erode the contacts and
shorten its life significantly?

If it helps evaluate the situation, take as an example two
cross-coupled NAND gates in the classic toggle switch
configuration. As a bias to determine the initial state, say
one input of one NAND element has the small cap to ground
and is tied to Vdd via a resistor of ~100k. The microswitch
parallels the capacitor. Is it advisable to insert a series
resistor to limit the discharge current?

put an R in series with the switch...

We short out large charged loads of 20Vk or more with a 10Watt 25k
R and the crow bar contacts last a long time!

When I say large I mean large cables of 10,000 feet of more with lots
of dielectric charge using 20kV or more.

Jamie

 

[Pimpom]

[email protected]
says...
It is done everyday.
Pull up resistor, debounce capacitor, mechanical switch.
Every video game in America has one somewhere.

The video game controllers I know about usually use printed
carbon contacts that are inherently resistive. I meant
discrete switches with metal contacts.