I have one of these transmitter modules attached to an Arduino Mega and currently powered by the Arduino Mega 5v pin. I have locations that cannot receive the radio transmission because of lack of power so I need to boost the power transmitted and wish to transmit using 12v power supply.
It would have been easier to append this question to this post. However I can't do that because I don't have enough points.
- I see that this circuit will work. Can someone recommend a specific component / characteristics for the transistor. T1 NPN seems to me a genetic type.
- Can someone recommend a specific (240vac to) 12v supply. (I can remember V=IR and the basics of Ohms law but can't remember what determines how much current is drawn by a load).
- It seems to me that a mains powered 12 volt supply and arduino board ground should not be mixed, so how do I wire this up? Is it a case of simply attaching 12v -ve terminal to GND as shown in the circuit?
ps for switching speed considerations, my Arduino transmission pulse/ pin is typically 275uSecs HIGH then 115uSecs LOW (or in reverse order). Mostly I shoot 25 of these sequences at once. Then I have some slower pulses at 1168uSecs HIGH and 397uSecs LOW.