Running 3 motors in circuit, where to insert lipo alarm?

[Stoph]

Hi all!

I'm working off of this schematic for a modded Nerf blaster (note: schematic not my own work).

I am hoping to hook up a little lipo alarm (http://rcbitz.com.au/images/MiniLipoAlarm.jpg ) somewhere in there to display the voltage of my 1s lipo I'm using to power it.

Question:
Where can I put it that it will read the voltage, and will running 3 motors intermittently cause false readings?

Hope that makes sense!

- C

 

[mfb]

Just the voltage of the power supply? Connect it in parallel to the power supply. Depending on the motors, the voltage might oscillate a bit, then the displayed voltage will depend on details of the voltage measurement. An additional capacitor could reduce those oscillations.

 

[Stoph]

Just the voltage of the power supply? Connect it in parallel to the power supply. Depending on the motors, the voltage might oscillate a bit, then the displayed voltage will depend on details of the voltage measurement. An additional capacitor could reduce those oscillations.

Thanks! That helps.

So a capacitor would smooth out any spikes to both operation of motors and readout of voltage, yes? Any cap size recommendations? And that would go parallel into the circuit before or after the voltage meter? Thanks!

 

[mfb]

So a capacitor would smooth out any spikes to both operation of motors and readout of voltage, yes?

Right.

Any cap size recommendations?

Enough to not get drained significantly within one revolution of the motors. Maybe even larger if you want to change the motor power frequently.

And that would go parallel into the circuit before or after the voltage meter?

There is no before and after. Both parallel to the power supply.

 

[Stoph]

Right.
Enough to not get drained significantly within one revolution of the motors. Maybe even larger if you want to change the motor power frequently.
There is no before and after. Both parallel to the power supply.

Champion! Thanks mfb!