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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?

Thanks

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  • \$\begingroup\$ a switch ie on/off or remote? \$\endgroup\$ – Solar Mike Aug 15 '17 at 8:17
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For this sort of situation, I usually go for the following circuit.

schematic

simulate this circuit – Schematic created using CircuitLab

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.

schematic

simulate this circuit

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.

schematic

simulate this circuit

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  • \$\begingroup\$ is there any simple circuit, only with a single or two items in the circuit,by the way i am using 3.3V system \$\endgroup\$ – Mudassir Hussain Aug 15 '17 at 8:22
  • \$\begingroup\$ If the voltages are the same, a simple N-MOSFET will probably do. You can pull-down the command to make sure the supply of the SD card is off by default. \$\endgroup\$ – Edesign Aug 15 '17 at 8:26
  • \$\begingroup\$ Which N-Mosfet? Can you please provide me any part number, which will be commonly available. \$\endgroup\$ – Mudassir Hussain Aug 15 '17 at 8:33
  • \$\begingroup\$ A 2N7000 is a commonly available N channel MOSFET, whether it is suitable will require you checking its parameters on it's datasheet. \$\endgroup\$ – Colin Aug 15 '17 at 8:40
  • \$\begingroup\$ I will get few 2N7000 MOSFETs from the local market and will have a try. Thank you very much \$\endgroup\$ – Mudassir Hussain Aug 15 '17 at 9:23

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