I am working on a project, where I need to switch ON and OFF power going to an SD card. What should I use?
Can I use a BC547 as a switch? Will that help?
For this sort of situation, I usually go for the following circuit.
The transistors to be used and the values of the resistors will depend on the voltages you are using. And as a bonus, the voltages for the power supply and for the command can be different!
EDIT:Because both voltages are the same, you can connect directly the P-MOSFET to the command. You can use the BS250.
You could also use an N-MOSFET on the ground path. As Colin suggested in the comments, the 2N7000 (or 2N7002 for SMD) is a good example.