Hi there,
I'm attempting to use a PN2222A NPN-type transistor to power a 5VDC relay, using my Raspberry Pi as the power sources for the collector and base. For reasons I cannot comprehend (though I'm sure one of you bright people would know...), when the base is set to 3.3v, the emitter only reads 2.9v. I expected it to read much closer to 5v.
For simplicity's sake, I've removed the relay from the entire equation for the time being, and have simply made the following connections:
Any ideas how I can get the expected 5v reading from the emitter of the transistor? Or, is it more likely that my transistors just duds?
Thanks!
I'm attempting to use a PN2222A NPN-type transistor to power a 5VDC relay, using my Raspberry Pi as the power sources for the collector and base. For reasons I cannot comprehend (though I'm sure one of you bright people would know...), when the base is set to 3.3v, the emitter only reads 2.9v. I expected it to read much closer to 5v.
For simplicity's sake, I've removed the relay from the entire equation for the time being, and have simply made the following connections:
- Connected the Pi's 5v pin to the collected of the transistor, via a 1kOhm transistor.
- Connected the Pi's GND to the emitter (in lieu of the relay).
- Connected the Pi's 3.3v pin (in lieu of a GPIO) to the base of the transistor, via a 1kOhm transistor.
Any ideas how I can get the expected 5v reading from the emitter of the transistor? Or, is it more likely that my transistors just duds?
Thanks!
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