PNP Bipolar Junction Transistor (BJT) switches let you switch from the high side of the circuit.
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Base resistor must provide enough signal current to saturate (fully turn on) the PNP transistor when the switch is closed. A 10KΩ resistor typically works well. The transistor must be able to handle the current demands of the load.
The 2N3906 has a maximum of 200mA of collector current. As always, consult the component datasheet of the particular component you are using for the most accurate specifications.
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