Thanks for the reply!

Is it possible to use a thicker stencil to accurately place solder paste on a PCB and reflow solder DIP components in a reflow oven (+flux spray)?
Will it produce a defect-free and solid bond? Have anyone tried this before?

Thanks for the help!

Is CADSOFT's EAGLE capable of producing nets like in pic2 instead of pic1? How to do it or any other software recommendations?


pic1


pic2

Is the LM317's maximum output at 1.5A? Can it handle over 1.5A of current (not output, handle)?

Confused again. So if I had a 12V 0.5A (6W) power source, and I want a converted voltage of 6V. I will have my output at 6V 0.5A? or 6V 1A ?(Power=Voltage x Current = 6W)

So, It'll depend on the power source, right?

One more Q, if I input a 12V 0.5A (6W) into the LM317 and expect a 6V output from the LM317, will I get a 1A output current? (Because 6W)

• Will I get a constant 1.5A output current (as stated in the datasheet) although having a power source which its current is lower?
• Although having 6V as the power source, can I get the output voltage at 12V and also constant 1.5A output current?

Can anyone answer my questions and tell me more about it? Began to get confuse on voltage regulators.

Datasheet: http://www.national.com/ds/LM/LM117.pdf

Is it possible to save money to buy a GSM/GPRS modem by having a connection to a mobile phone to send AT commands? How to actually bring out their RX and TX pins in a phone (Nokia preferred)?

[data out]

ya, just connect data out of the 1st IC to the data in of the 2nd IC, data out of the 2nd IC to the data in of the 3rd IC....
connect all clock and latch pins to the same output of the Arduino. On the programming, you need to use the shiftOut function 3 times continuously. So, the 1st shiftOut will go to IC 1. But when you shiftOut the 2nd time, the 1st shiftOut binary data will be pushed to the 2nd IC, and so on...

-Why not use 4 NPN transistors but use 2 NPN and PNP transistors?
-What is the use of the diode in this circuit?

Check out: http://www.robotroom.com/BipolarHBridge.html

What is the difference between NPN & PNP transistors?
Does NPN transistors activate by connecting its base to Vcc? and connecting the base of a PNP transistor to ground will activate it?
(NPN: collector-positive; emitter-negative; base-positive || PNP: collector-negative; emitter-positive; base-negative;) Correct?

What is the main use of the MAX232? If a FTDI chip us used with a USB connector, will I need to use the MAX232?

Can the capacitor of the circuit be non-polarized? What is the difference between a polarized cap and a non-polarized one?