Attached is a modified circuit that will drop out of the Sequential Mode if the brakes are pumped but then stay on. Now if the brakes are pumped, both lights will sequence until about a second after the pumping stops and the brakes steadily applied. C9, D2, and R8 were added so that the Pulse Detector responds only to pulse edges, not DC levels. Previously a continuous "high" on the input would cause the Pulse Detector output to stay high. Also had to modify the values of R1 and C1 to accommodate this difference.
I also changed Q1 to a MOSFET (M1) since I realized that the 5V reverse base-emitter voltage rating was being exceeded (that's not modeled in LTspice). M1 can be just about any N-MOSFET.
Edit: An NPN transistor, such as a 2N2222(A) could also be used in place of MOSFET M1 (with a ≈50k resistor in series with the base).
There were a few other changes to correct another race condition I noticed.
View attachment Taillight Sequencer 2.asc
I also changed Q1 to a MOSFET (M1) since I realized that the 5V reverse base-emitter voltage rating was being exceeded (that's not modeled in LTspice). M1 can be just about any N-MOSFET.
Edit: An NPN transistor, such as a 2N2222(A) could also be used in place of MOSFET M1 (with a ≈50k resistor in series with the base).
There were a few other changes to correct another race condition I noticed.
View attachment Taillight Sequencer 2.asc
Last edited: