Hi all, I am designing a project that I want to run off an ATX PSU and I wanted to use a push button for the On/Off mechanism, just like a desktop PC.
I have uploaded a design for a circuit in Eagle (lite) which I think will work. It uses the +5v standby voltage the ATX PSU provides to power a J-K flip flop (POWERA on the schematic) (schematic stolen from Instructables here), which I have linked to a transistor which then pumps the +5v standby into the ATX PSU's Power On signal line.
So far the design is purely schematic, I haven't tried wiring it up or any testing, I don't really have the parts as yet, I just want to know if it looks legit.
Also, unless I've misread on how the flip-flop works, am I right in thinking that the two outputs Q/!Q will toggle between one and the other when S1 is pressed, effectively showing my 'Standby' and 'On' LED's?
Ignore the USB bit... the end goal for this is to power a RasPi with some other bits and pieces in a 2U rack mount enclosure where I can toggle and monitor several mains (IEC) sockets to manage a load of Cisco routers/switches.
I know I need some proper values for the transistor and some of the resistors but it was just to get me started.
Let me know what you think.
Thanks
I have uploaded a design for a circuit in Eagle (lite) which I think will work. It uses the +5v standby voltage the ATX PSU provides to power a J-K flip flop (POWERA on the schematic) (schematic stolen from Instructables here), which I have linked to a transistor which then pumps the +5v standby into the ATX PSU's Power On signal line.
So far the design is purely schematic, I haven't tried wiring it up or any testing, I don't really have the parts as yet, I just want to know if it looks legit.
Also, unless I've misread on how the flip-flop works, am I right in thinking that the two outputs Q/!Q will toggle between one and the other when S1 is pressed, effectively showing my 'Standby' and 'On' LED's?
Ignore the USB bit... the end goal for this is to power a RasPi with some other bits and pieces in a 2U rack mount enclosure where I can toggle and monitor several mains (IEC) sockets to manage a load of Cisco routers/switches.
I know I need some proper values for the transistor and some of the resistors but it was just to get me started.
Let me know what you think.
Thanks