# Motor in a parallel circuit slowing down, how can I speed it up?

I have a simple circuit, with 5x 3v/20ma LED's in parallel (each with a 330 resister in front of them) and a dc motor (rated 6v to 24v) also in parallel, all running off a 9v battery.

The problem is the motor is slowing down thanks to the LED's. I would have thought that with having everything being in parallel the motor would not be slowing down, but it is.

What is happening here? Why is it slowing down? Is it to do with the voltage, or the current (amps)?

Can I speed the motor up using a transistor, or is there something else I can use to speed it up?

Thank you!

• Put a voltmeter on the 9 V battery terminals. Observe the voltage without the motor attached, but with the LEDs attached. Then, while still observing, add the motor and see what voltage you get.
– jonk
Commented Dec 21, 2016 at 22:23
• First, measure the voltage of the battery with the motor not running, then with it running. Does the voltage drop significantly? EDIT: jonk, you beat me to it. Commented Dec 21, 2016 at 22:23
• A cheap fix is using the same type of battery in parallel with the current battery to double the amount of amps you can pull. There's some drawbacks, but you might just be interested to see what it does for yourself.
– Mast
Commented Dec 21, 2016 at 22:43
• Don't put them in series, put them in parallel. You really want to take a beginner course in electronics to answer the rest of your questions. There's plenty of things you can do with a transistor, but none of them make sense in the context you provided. More parallel batteries or less parallel LEDs. Once you can handle a large load all at once, increasing the voltage by using series batteries could work.
– Mast
Commented Dec 21, 2016 at 22:51
• No, that will cripple both your LEDs and motor. Don't do that.
– Mast
Commented Dec 21, 2016 at 23:04