Hi,
I am trying to build a one shot circuit with NE555 timer IC, my requirement
is when the trigger pin shorted to ground, the output should provide a short
delay switch to logic high then back to logic low. However, according to my
experiment, it shows that if the trigger input after shorted to ground, the
output with keep to logic high until the input (trigger) pin disconnect for
the ground.
Please suggest if any NE556 connection circuit or any other simple circuit
can fulfill my requirement.

Regards
Victor

"KK" wrote in message
...
Hi,
I am trying to build a one shot circuit with NE555 timer IC, my
requirement
is when the trigger pin shorted to ground, the output should provide a
short
delay switch to logic high then back to logic low. However, according to
my
experiment, it shows that if the trigger input after shorted to ground,
the
output with keep to logic high until the input (trigger) pin disconnect
for
the ground.
Please suggest if any NE556 connection circuit or any other simple
circuit
can fulfill my requirement.

Regards
Victor




Have the switch ac coupled to the input of the 555. Or, you could use a
one-shot, like a 74LS123.
Brian

invert the trigger input

Brooks

KK wrote:

Hi,
I am trying to build a one shot circuit with NE555 timer IC, my requirement
is when the trigger pin shorted to ground, the output should provide a short
delay switch to logic high then back to logic low. However, according to my
experiment, it shows that if the trigger input after shorted to ground, the
output with keep to logic high until the input (trigger) pin disconnect for
the ground.
Please suggest if any NE556 connection circuit or any other simple circuit
can fulfill my requirement.

Regards
Victor