DRIVER Q: Multiple Circuits in One Build???

[IsaacT]

Hey guys,

I am prepping an exciting build and I need to power to different things. One of these is my diode, which will be using a 2-cell Lithium Ion setup and the other will be a circuit board which is controlling a speaker. It is a soundcard setup and it will take a max of a single lithium ion cell.

So I need to have a 2-cell input for the build, but I need these guys on completely different circuits.

So for the diode it will go:
Battery -> Toggle Switch -> Driver -> Diode -> Battery

And then for the soundboard:
Batteries -> Bucking Driver(?) -> Soundboard -> Momentary Switch -> Speaker -> Batteries

I am hoping this would work? Obviously I need the driver for the soundboard to be a voltage regulator circuit.

BUT. Will it even work? The build would end up having 2 switches. One for contant on laser diode and one momentary to trigger the sound on or off. This is fine by me. But will using different drivers be a problem? I am thinking it would be fine as long as I keep them on separate circuits.

Let me know,
-Isaac

PS - THANK YOU FOR ANY HELP!!!!

 

[ARG]

You can do one switch if you want, just have it as

Batteries -> Switch -> Drivers -> Circutry

You can also do two switches just fine. What you proposed would work.


Lastly:

I need to power to different things.

 

[IsaacT]

Sorry typing on phone is bad lol.

And I would use one switch but it has to be momentary. Each time the connection is made it alters the state of the soundboard to start or stop.

Is there a driver or voltage regulator you would recommend to drop two battery voltage level to 3.7V?

 

[ARG]

Well, if it's designed to run off of one Li-in it should be able to take 4V just fine, you can get 4V regulators on digikey for under a dollar.
See P/N: MCP1702-4002E/TO-ND

That or use an LM317 with a couple of resistors to get 4V.

 

[Sigurthr]

Or you could center tap the battery connection. Not the easiest to do depending on host/enclosure but it would be the easiest electrically.

 

[BShanahan14rulz]

I like ARG's idea. you waste a bit in the regulator, but make up for it by not having a complicated battery compartment.

You want to be careful with draining one cell faster than the other with cells in series, so if you go that route, keep an eye on both cells' voltages.

 

[IsaacT]

Well the soundcard is getting ditched so no worries.