If this question does not belong in this thread then i apologize.
Ok so heres my question:
First off im basing this all off of this link (not really important): http://www.streettech.com/modules.php?op=modload&name=News&file=article&sid=1375
the schematic im referring to is: http://www.streettech.com/storypics/BEAMSEVAR.jpg
the paragraph on that page reads:
"The solar cell charges the main capacitor until the voltage is high enough for the FLED to start flashing. When the FLED flashes, current flows through the FLED and the base of the PNP transistor and it turns on. Now current passes through the PNP into the base of the NPN transistor and it turns on.
When the NPN turns on the collector which is connected to the motor and the 2.2K resistor goes low (to GND)...."
Now can someone explain how a pnp transistor works? from what Ive played with using the arduino, if i make a signal HIGH into the base the pnp transistor then it doesn't work. If i make it LOW then it turns on and current flows from the collector to the emitter. So doesn't that contradict the above paragraph where the PNP is turned on by giving it a current?
my understanding of basic transistors is:
NPN< apply current to the base and it 'connects' the collector and emitter
PNP< apply current to the base and it cuts off the collector emmiter connection.
Now clearly this isnt the case for PNP, because if i just put 5 volts to collector and the emmitter to ground ( and a led in the circuit) then nothing happens until the base is give a "LOW" signal.
Im utterly confused, for those who actually read through this and comment i thank you in advance.