help for timelapse slider motor circuit
DC motors will run at a speed set by the supply voltage. Speed will drop as the motor is loaded but the resultant increase in current will give more torque tending to bring it back up to nominal speed for that voltage.

Powering from a lower voltage will not break the motor.







simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. 8-speed motor control with forward/reverse and limit switches.



Figure 2. 12-way rotary switch.

Using eight 1.5 V batteries and a 12-way rotary switch you can create the 8-speed motor control circuit shown in Figure 1.


Set the stop tab on the switch so that there are nine positions available.
Leave position 1 as the 'OFF' position and wire up the next eight positions as shown in Figure 1.
The limit switches will stop motion at the end of travel so you can leave the unit unattended.
The FWD/REV switch ...


Note that using anything other than full voltage will cause the cells to run down unevenly but you can address this by swapping out BAT1 with BAT8, etc. to even out the life.

To work out battery life look up the mAh of the battery, measure the current into your motor (mA) and lifetime in hours = mAh / mA. (The milli-amps cancel out leaving you with hours.)

Get the 'break before make' version of the switch. This version prevents momentary shorting of, for example, BAT4 as you switch from SW4 to SW5.