hi everyone, im looking for some thoughts and ideas.
im currently working on a project circuit that will select between two different input signals and send them to a single output without altering the voltage. the input signals are both constantly fluctuating 0-1000 mV positive signals coming from two different voltage generating sensors. since theyr both sensor signals any alteration to the voltage with affect the accuracy of the computer. so alteration is unacceptable.
the signal that causes the switch from signal A (the primary normaly closed circuit) to signal B is +12V. when voltage is applied to the switch signal the circuit needs to switch to signal B, and when the voltage is removed it needs to automatically switch back to signal A. the computer needs to be receiving a signal from the output at all times.
i have worked with using an RS flip-flop for this job but it would require 2 nands gates and FOUR transistors (2 NPNs to use the positive output of the RS to switch the PNPs controling the signals). this design might work but im not sure.
attached is a diagram of a different circuit ive designed that i believe may work, but the issue is that the output of the inverter circuit used to operate the transistor on input A is positive. since transistor A is of the PNP type a positive signal there does not work. perhaps using an NPN transistor inline with the base of the PNP would solve the problem.
if you have any thoughts or ideas or corrections to my logic please do post a reply and let me know. ive been trying to find the simplest method to achieve my goal of switching between 2 unaltered signals and havent really gotten too far. i hope members of this forum can help me succeed with this project.
thanks for reading
jeff
im currently working on a project circuit that will select between two different input signals and send them to a single output without altering the voltage. the input signals are both constantly fluctuating 0-1000 mV positive signals coming from two different voltage generating sensors. since theyr both sensor signals any alteration to the voltage with affect the accuracy of the computer. so alteration is unacceptable.
the signal that causes the switch from signal A (the primary normaly closed circuit) to signal B is +12V. when voltage is applied to the switch signal the circuit needs to switch to signal B, and when the voltage is removed it needs to automatically switch back to signal A. the computer needs to be receiving a signal from the output at all times.
i have worked with using an RS flip-flop for this job but it would require 2 nands gates and FOUR transistors (2 NPNs to use the positive output of the RS to switch the PNPs controling the signals). this design might work but im not sure.
attached is a diagram of a different circuit ive designed that i believe may work, but the issue is that the output of the inverter circuit used to operate the transistor on input A is positive. since transistor A is of the PNP type a positive signal there does not work. perhaps using an NPN transistor inline with the base of the PNP would solve the problem.
if you have any thoughts or ideas or corrections to my logic please do post a reply and let me know. ive been trying to find the simplest method to achieve my goal of switching between 2 unaltered signals and havent really gotten too far. i hope members of this forum can help me succeed with this project.
thanks for reading
jeff