BACKGROUND INFORMATION IF DESIRED:
I have a sensor (MQ7 Carbon monoxide sensor) that needs to be switched between 5v and 1.4v. What I did was create a voltage divider in series attached the source of an N-channel mosfet, with the source being pulled up to 5v. So, when the gate has 'off', I'll have my 5v, and when the gate 'on' current is allowed to flow through the mosfet to ground thus completing the voltage divider and giving me my 1.4v when desired.
ASSISTANCE NEEDED:
I have buffer between this voltage and my sensor. Currently in simulations, I'm using a basic 741 op amp. With no sensor attached, the output voltages are fine, but once I attach my sensor (internal resistance of 30 ohm) the op amp essentially shuts down and my voltage at the output of the buffer is in the milli volt range. A professor told me that the 741 doesnt have the power capability since 5 volts at the output and a resistance of 30 ohms gives .83 W (p = v^2/r), and I noticed the 741 can handle power dissipation of 500 mW. Would anyone have any suggestions on an op amp, ideally only powered with 0v to 5v and ground, that can handle this capability? I'm having trouble reading in datasheets this information as it was easily listed in the 741 datasheet.
I realize this is extremely long so any assistance would be greatly appreciated. Long time lurker, first time posting!
I have a sensor (MQ7 Carbon monoxide sensor) that needs to be switched between 5v and 1.4v. What I did was create a voltage divider in series attached the source of an N-channel mosfet, with the source being pulled up to 5v. So, when the gate has 'off', I'll have my 5v, and when the gate 'on' current is allowed to flow through the mosfet to ground thus completing the voltage divider and giving me my 1.4v when desired.
ASSISTANCE NEEDED:
I have buffer between this voltage and my sensor. Currently in simulations, I'm using a basic 741 op amp. With no sensor attached, the output voltages are fine, but once I attach my sensor (internal resistance of 30 ohm) the op amp essentially shuts down and my voltage at the output of the buffer is in the milli volt range. A professor told me that the 741 doesnt have the power capability since 5 volts at the output and a resistance of 30 ohms gives .83 W (p = v^2/r), and I noticed the 741 can handle power dissipation of 500 mW. Would anyone have any suggestions on an op amp, ideally only powered with 0v to 5v and ground, that can handle this capability? I'm having trouble reading in datasheets this information as it was easily listed in the 741 datasheet.
I realize this is extremely long so any assistance would be greatly appreciated. Long time lurker, first time posting!