While working on some of the adaptive toys(Star master light) it became apparent that a latching switch would be a better fit for certain functions than the momentary ones currently in use.
In discussions with @MMC_Jake it seems the preferred approach is to have a separate device that interfaces with existing switches rather than a redesign of the switch to hold an off the shelf latching switch.
On the surface this seems to be a relatively easy build but I’m pretty new to MMC so am not aware of all the situations that the switch may be used in.
Certainly for toy adaptations, I think something like the attached would suffice
We could certainly use mosfets if necessary and fiddle with the RC values to ensure the switch doesn’t oscillate if held down too long.
There is another similar circuit from EEVblog that may be a little more thought out (in particular his final design doesn’t draw any power when the switch is off.). Comment section has a recommended change.
One factor to consider is the need to get Vs and ground to the latch. For most toys we could simply pull that from the mono cable or use something like the battery interrupter .
Appreciate any thoughts or input. I know just enough to be dangerous about electronics so would welcome any comments, including whether this is worth pursuing.