Help a beginner project! -LEDs & Motors for child's playboard

Thread Starter

Tlarsen93

Joined Nov 24, 2017
3
I am building an entertainment board for my niece. It will have all kinds of things for her to play with and develop her motor skills on including various types of latches and locks. I want to include an assortment of four LEDs and three small motors that spin her favoritecartoon characters each activated by a different type of switch (toggle, rocker, temporary push button, key activated, chain pull...) . I have the carpentry part down and everything is mounted but I don't know the best way to wire them to a single battery pack.

Each LED is 12v 10mm and says it has a built in integral resistor on the package.

The motors are rated .5-3.0 v

Would 4 AA batteries be OK to power the board? (I am intending only one thing be on at a time but she is a kid and will probably turn on multiple)

In summary, I have a battery power supply, four LEDs with a switch next to each one and three motors with switches next to each one. How do I properly connect them all?
 

DickCappels

Joined Aug 21, 2008
6,649
It is ok to use 4 AA cells but 8 eight would be better for the LEDs and two would be better for the motors.

The LED might not be bright enough. I suggest that you actually try an LED at 5 volts and whether you like the way it looks.

@MaxHeadRoom is the one I would expect to give better advice on the motor.
 

Thread Starter

Tlarsen93

Joined Nov 24, 2017
3
It is ok to use 4 AA cells but 8 eight would be better for the LEDs and two would be better for the motors.

The LED might not be bright enough. I suggest that you actually try an LED at 5 volts and whether you like the way it looks.

@MaxHeadRoom is the one I would expect to give better advice on the motor.
Thank you for the reply, I will definitely get another battery holder and do the LEDs and motors separately.

That still leaves the actual wiring. Do I need any other components or do I just wire them in parallel directly to the batteries?
 

DickCappels

Joined Aug 21, 2008
6,649
From what you have posted all the major components you need are switches (or buttons), the motors, lights and batteries. Yes, put the motors and switches through their switches to put them across their respective batteries when the switches are actuated.
 

Thread Starter

Tlarsen93

Joined Nov 24, 2017
3
I am now thinking of using a rechargeable 12v drill battery to power the board. From what I understand, this would be OK for the LEDs, but too high for the motors. Could I put an appropriate resistor on each motor to reduce the voltage to 3v?
 

DickCappels

Joined Aug 21, 2008
6,649
Maybe. It probably would not hurt to try. If you measure the motor current under load you can calculate a resistor value. There might be a problem with the motor starting because until the armature starts spinning the motor will appear to be a lower resistance and thus the voltage across the motor will be lower than when it is running.

I don't know any way to tell whether it will start ok without performing the experiment.
 

Bernard

Joined Aug 7, 2008
5,686
If you already have the 12 V battery then I would use a buck converter for the highest motor V & add a resistor for lower V motors.
If starting from scratch, 4 NiMH, AA's, plain 10 mm LEDs with added resistors & resistors for motors as required. Do you need a lockout circuit so that only one switch at a time can be used ?
 
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