Hi guys,
Could anyone suggest a suitable switch for the following operation?
Objective:
SW1 is normally closed (N.C.) since buck #1 is the main operator. SW2 normally open (N.O.) because it is used as a backup.
Both SW1 & 2 to be controlled with 8051 logic level, that is, 0V for LOW and 3.3V for HIGH.
Average current through each switch is about 1A, therefore I'm selecting a 2X1A = 2A rated current SW for tolerance.
Absolute voltage = +100V DC with respect to GND, but potential difference (P.D.) across the switch terminals really depends on the R(on).
Operation:
When a fault occurs at Buck #1 (short or open circuit), the 8051 MCU detects and turn off SW1 and on SW2 simultaneously. The step-down operation is transferred from Buck system #1 to #2.
I've searched through the internet and has narrowed down to 2 options.
Attached is my operation layout to facilliate better understanding.
Thanks in advance!
Could anyone suggest a suitable switch for the following operation?
Objective:
SW1 is normally closed (N.C.) since buck #1 is the main operator. SW2 normally open (N.O.) because it is used as a backup.
Both SW1 & 2 to be controlled with 8051 logic level, that is, 0V for LOW and 3.3V for HIGH.
Average current through each switch is about 1A, therefore I'm selecting a 2X1A = 2A rated current SW for tolerance.
Absolute voltage = +100V DC with respect to GND, but potential difference (P.D.) across the switch terminals really depends on the R(on).
Operation:
When a fault occurs at Buck #1 (short or open circuit), the 8051 MCU detects and turn off SW1 and on SW2 simultaneously. The step-down operation is transferred from Buck system #1 to #2.
I've searched through the internet and has narrowed down to 2 options.
- Mechanical switch (relay)
- Slower response but totally cut off operation with no leakage current
- Not sure if a relay could be controlled by 3.3V logic levels output? Even if it could, would it be safe as 1 terminal = +100V, and the other to 3.3V?
- Electronic switch (MOSFET)
- Any off-the-shelves unit where I could conveniently connect this SW with my existing system? Perhaps with 3 pins; PIN 1 -> +100V DC input; PIN 2 -> Buck convertor; PIN 3 -> logic level?
- Or do I need to design from scratch an appropriate switching circuit with the use of MOSFET? I did see a few schematics online but those are like for lower voltage system in the range of 12V to 20+ V?
Attached is my operation layout to facilliate better understanding.
Thanks in advance!
Attachments
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