SecularSam
New Member
The schematic was done in Visio drawing.
SATA HD SWITCH Specification
A device that switches SATA hard drives at the push of a button.
It will allow the user to select one of three SATA hard drives. The front panel will have only three illuminated buttons. One button will always be illuminated indicating the hard drive in use.
To select a hard drive the user must push a button that will:
A) Blink. The blink acknowledges the selection.
B) Wait five seconds before initiating the computer to shut down. The five-second delay is provided to give the user a chance to cancel the operation.
C) If the operation is to be canceled, the user must push the same button again. Once this is done, the button will no longer blink. The two remaining buttons are disabled while the selected button is blinking.
D) If the operation is to proceed, the user will allow the five-second delay to expire and the computer will commence a shutdown. During this time, the button will continue to blink.
E) Once the computer powers down the blinking will stop and the button will stay illuminated while the previous selected hard drive button will no longer illuminate.
F) Approximately five seconds after shut down, the computer will power back up.
The user will not be able to turn off a hard drive in use. The only way to turn it off is to select another hard drive and allow the sequence described above to be completed.
When the computer is powered down normally the user has the option to select the desired hard drive. Remembering that one button will always be illuminated, whichever of the two hard drives are selected, it will deselect the one previously chosen.
Design Rationale
Motivation:
The design and development of this device is motivated from the desire to:
The device should be modular, self contained with minimal electrical interfacing. Connectors and ports must be easily accessible. The user interface must be easily viewable with controls situated in an unconfused and intuitive manner.
Electrical considerations:
Contemporary computer power supplies provide a +5 VDC when powered down. This voltage is referred to as Stand-by supply. It is present as long as the power supply is connected to the 120 VAC and is not switched off. This feature will be utilized as it will be necessary to maintain control while the computer is powering down during a controlled reset sequence.
TBD
Complete Schematic:
Add power interface.
Component selection:
Locating a:
SATA HD SWITCH Specification
A device that switches SATA hard drives at the push of a button.
It will allow the user to select one of three SATA hard drives. The front panel will have only three illuminated buttons. One button will always be illuminated indicating the hard drive in use.
To select a hard drive the user must push a button that will:
A) Blink. The blink acknowledges the selection.
B) Wait five seconds before initiating the computer to shut down. The five-second delay is provided to give the user a chance to cancel the operation.
C) If the operation is to be canceled, the user must push the same button again. Once this is done, the button will no longer blink. The two remaining buttons are disabled while the selected button is blinking.
D) If the operation is to proceed, the user will allow the five-second delay to expire and the computer will commence a shutdown. During this time, the button will continue to blink.
E) Once the computer powers down the blinking will stop and the button will stay illuminated while the previous selected hard drive button will no longer illuminate.
F) Approximately five seconds after shut down, the computer will power back up.
The user will not be able to turn off a hard drive in use. The only way to turn it off is to select another hard drive and allow the sequence described above to be completed.
When the computer is powered down normally the user has the option to select the desired hard drive. Remembering that one button will always be illuminated, whichever of the two hard drives are selected, it will deselect the one previously chosen.
Design Rationale
Motivation:
The design and development of this device is motivated from the desire to:
- Run different operating systems on a single computer.
- Ability to select the operating systems with ease.
- Eliminating multiple steps to accomplish the task.
- Eliminate the chance to accidentally switch to another SATA drive during the use of another.
- Have a minimal learning curve in order to operate the device.
The device should be modular, self contained with minimal electrical interfacing. Connectors and ports must be easily accessible. The user interface must be easily viewable with controls situated in an unconfused and intuitive manner.
Electrical considerations:
Contemporary computer power supplies provide a +5 VDC when powered down. This voltage is referred to as Stand-by supply. It is present as long as the power supply is connected to the 120 VAC and is not switched off. This feature will be utilized as it will be necessary to maintain control while the computer is powering down during a controlled reset sequence.
TBD
Complete Schematic:
Add power interface.
Component selection:
Locating a:
- Project box made to fit into a 5.25 inch bay.
- 15 pin SATA power connector mounted either as a right angle board or bulkhead configuration.
- I am determined to use illuminated push buttons which are expensive. What's listed in the BOM may change.
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