Calculating resistor values

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xmen_xwk

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I have this schematic but I'm bit confuse about the resistor values.


How do I make sure I'm using the correct values ?

The MOSFET is Si7157DP, Transistor is **broken link removed** and signal is 5V.
 

This will not work. You have to move the load under the transistor, or use p-channel mosfet with pull-up resistor to gate to perform closing it.
 

Circuit uses PMOS and thus will work.

Resistor values aren't particular critical, you can leave them as is. Base resistor value might be factor 10 higher without problems.
 
Easyrider83 said:
This will not work. You have to move the load under the transistor, or use p-channel mosfet with pull-up resistor to gate to perform closing it.
Click to expand...


Why would it wont work ? There is a P Channel Mosfet with pulled up resistor. Moving load under the transistor makes no sense at all. The transistor is only for opening MOSFET, not for switching 2A load. Maybe I'm wrong but its better to point out the mistake than just saying wont work.

- - - Updated - - -

FvM said:
Circuit uses PMOS and thus will work.

Resistor values aren't particular critical, you can leave them as is. Base resistor value might be factor 10 higher without problems.
Click to expand...
Alright but I put 1K just as a guess. Thank you.
 

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