My knowledge of electrical engineering isn't great but faced with a challenge I do have a habit of learning enough to see it through. There is a probably a very simple solution to this.
I've been pondering different routes to achieve a 'chuffing' smoke effect on a model train. I'm looking to use a Hall effect sensor to pick up 4 magnets spinning on the axle of the train. Each detection triggering a puff of smoke up the chimney.
To generate the smoke I'm going to be using a vape heating coil of 1.5ohms. There will also be a small 3V fan in an enclosure with the coil to ensure there is airflow and push the vapour out the chimney. Total load would be a smidge over 2amperes at 3V.
However, I would like the fan and coil to be continuously powered at a base load so there is always a little activity. I would then like the Hall effect sensor to come into play to produce 'chuffs' of more intense blasts when the locomotive moves.
There is 12VDC on the locomotive to utilise, but I've got some miniature variable voltage regulators (MP1584en) left over from another project. I was thinking I could use two of these to have a supply of 3V for the 'chuff/HIGH' and ~1.5V for the idle/LOW.
What I need is a way of switching between them with the Hall effect sensor.
I've got a few A3144 Hall effect sensors and some IRF9540N P channel MOSFETss that I was originally planning to use, but a second opinion wouldn't go amiss.
Thankyou to anyone who can spare me a few moments!
(ps. The more I think about this the more issues I for-see. If the locomotive were to stop in a position where the Hall effect sensor was activated, it would be good to have a way to default back to the lower voltage state after a few seconds.)