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relay based power on after failure on pc

my bios is not doing it..


i think that the trigger has to be the 5 volt from my ATX power supply
that "says" (magenta color cable ) to the motherboard that is ready to
turn on
(and supplies the modem or and the network card if they are waiting a
signal to wake up on lan / or wake up on modem)

but here's the problem....

we have to make a circuit that..

... if there's 5 volt at the input ( and not below that ) then after
milliseconds.. the relay ( which is parallel to the on / off switch)

goes to the other position and turns on the computer..

but it can't stay at this position because it is like we hold still
the on/off button and you know if you hold it for 5 seconds it turns
of the computer.. so after let's say half of a second the relay must
go to it's first position
and stays there until the circuit loses for a long time eg 10 seconds
( avoid here micro-time-loss of network supply eg during a thunder
strike) and then .. having 5 volt input starts triggering / cycling
again....


for the 5 volt reference we 've got to have a 5V zener, for delay a
capasitor charging or an 555.. a classic relay.. but how the circuit
is gonna be?

.... here i need your help.. thanks for your time...





well alternatively .. we can trigger it , simple, with the 220 V from
the public network, but we must delay it so the ATX is ready
to give full power to all the pc parts....
 
E

ehsjr

Jan 1, 1970
0
my bios is not doing it..


i think that the trigger has to be the 5 volt from my ATX power supply
that "says" (magenta color cable ) to the motherboard that is ready to
turn on
(and supplies the modem or and the network card if they are waiting a
signal to wake up on lan / or wake up on modem)

but here's the problem....

we have to make a circuit that..

.. if there's 5 volt at the input ( and not below that ) then after
milliseconds.. the relay ( which is parallel to the on / off switch)

goes to the other position and turns on the computer..

but it can't stay at this position because it is like we hold still
the on/off button and you know if you hold it for 5 seconds it turns
of the computer.. so after let's say half of a second the relay must
go to it's first position
and stays there until the circuit loses for a long time eg 10 seconds
( avoid here micro-time-loss of network supply eg during a thunder
strike) and then .. having 5 volt input starts triggering / cycling
again....


for the 5 volt reference we 've got to have a 5V zener, for delay a
capasitor charging or an 555.. a classic relay.. but how the circuit
is gonna be?

... here i need your help.. thanks for your time...





well alternatively .. we can trigger it , simple, with the 220 V from
the public network, but we must delay it so the ATX is ready
to give full power to all the pc parts....

This will give you a ~ 1 second delayed negative at the
output after the 220 is restored:


------
| 12V +|-------+----+---[10K]----------+---> output
220===| | | | |
| | | [3.3K] |
| | | | 6.8V /c
| -|--+ [1K] +---[Zd]---[1K]---| NPN
------ | | | \e
| | [100uF] |
| | | |
+----+----+------------------+

After the power is restored the 100 uF will charge
through the 10K. When the charge reaches about 7.4 V
(in roughly one time constant [3.3K*100uF seconds])
the transistor will conduct and the output will go
negative.

You can couple that to the trigger of a 555 monostable
through a capacitor, and have the 555 operate your
relay.

Ed
 
E

ehsjr

Jan 1, 1970
0
ehsjr said:
my bios is not doing it..


i think that the trigger has to be the 5 volt from my ATX power supply
that "says" (magenta color cable ) to the motherboard that is ready to
turn on
(and supplies the modem or and the network card if they are waiting a
signal to wake up on lan / or wake up on modem)

but here's the problem....

we have to make a circuit that..

.. if there's 5 volt at the input ( and not below that ) then after
milliseconds.. the relay ( which is parallel to the on / off switch)

goes to the other position and turns on the computer..

but it can't stay at this position because it is like we hold still
the on/off button and you know if you hold it for 5 seconds it turns
of the computer.. so after let's say half of a second the relay must
go to it's first position
and stays there until the circuit loses for a long time eg 10 seconds
( avoid here micro-time-loss of network supply eg during a thunder
strike) and then .. having 5 volt input starts triggering / cycling
again....


for the 5 volt reference we 've got to have a 5V zener, for delay a
capasitor charging or an 555.. a classic relay.. but how the circuit
is gonna be?

... here i need your help.. thanks for your time...





well alternatively .. we can trigger it , simple, with the 220 V from
the public network, but we must delay it so the ATX is ready
to give full power to all the pc parts....

This will give you a ~ 1 second delayed negative at the ^
.33
output after the 220 is restored:


------
| 12V +|-------+----+---[10K]----------+---> output
220===| | | | |
| | | [3.3K] |
| | | | 6.8V /c
| -|--+ [1K] +---[Zd]---[1K]---| NPN
------ | | | \e
| | [100uF] |
| | | |
+----+----+------------------+

After the power is restored the 100 uF will charge
through the 10K. When the charge reaches about 7.4 V
(in roughly one time constant [3.3K*100uF seconds])
the transistor will conduct and the output will go
negative.

You can couple that to the trigger of a 555 monostable
through a capacitor, and have the 555 operate your
relay.

Ed
 
ehsjr said:
This will give you a ~ 1 second delayed negative at the
^
.33

output after the 220 is restored:
------
| 12V +|-------+----+---[10K]----------+---> output
220===| | | | |
| | | [3.3K] |
| | | | 6.8V /c
| -|--+ [1K] +---[Zd]---[1K]---| NPN
------ | | | \e
| | [100uF] |
| | | |
+----+----+------------------+
After the power is restored the 100 uF will charge
through the 10K. When the charge reaches about 7.4 V
(in roughly one time constant [3.3K*100uF seconds])
the transistor will conduct and the output will go
negative.
You can couple that to the trigger of a 555 monostable
through a capacitor, and have the 555 operate your
relay.

thamks, i 'll try it...
 
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