PNP darlington Pair calculation understanding

[Kranthikkenoch]

I have a 20ohms discharge resistor connected to my PNP darlington pair. I have simulated the circuit in my mobile (every circuit app).please find the attachment for circuit. But here I'm unable to understand how the PNP transistors are turned on. Please help me understand this circuit. Also while I'm ordering the components online and select Maximum collector current should be (+1A or -1A)

 

[dr pepper]

Conventional current flows from the + through the emitter, out through R8 or R10, then through the switch(s) to ground, this turns on the trans, pulling the collector close to +.