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Good day Picers
I am powering a RF Module from one of my PIC16F877's PINS.
The pic's pin only supply 25mA, I need 60mA.
I have connect the 2N2222A Transistor with a 680 Ohm resistor to my circuit to put the Amps a bit up, but when measuring with my multimeter between the positive and GND of the RF Module, it only supply me with 30mA.
What size resistor must I use to give me 60mA?
Some explanation about your scheme could be Welcome ...
DOZENS of supply schemes possible !!!
Alain
You could use three pins which you power up together, or that 2N2222 needs to be part of the ground return leg of your module. In other words, connect the Emitter to ground, Base to the PIC pin through a 4.7 K resistor, and the Collector to the ground side of your module. If I were to do it this way, I would put a bypass capacitor of .01 uF across the Emitter and Collector leads. To control the positive rail, the 2222 would be attached to the Base of a 3906 through a 2.2K resistor. The 3906 Base is also connected to it's Emitter through a 10 K resistor. The Emitter of the 3906 goes to the positive rail, and the positive side of the module connects to the 3906 collector. A high on the pin would turn the module on.
Ron
just Bias your base of your 2n2222 and connect the emitter to the ground, and the collector to your gadget...
You will draw your 60 mils... if you don't, then maybe your gadget does not need 60mils!...
Dwayne
Why power the module via its ground pin?
Not very safe practice.
AFAIK, the 2N2222 is a NPN device, so you'll have to conect its collector to the power rail, base via a 100r resistor to your output port, and the emitor to your module.
The output will be (power rail) 5v - 0.7 (transistor drop) = 4.3v
Cheers sda
Thank you very much for all the replies!!!