You are correct in your math
Yes, series is 1/2 the volt to each motor and the same current draw. Parallel is equal voltage with double the amps. Parallel would be preferred here but you must check the amp draw for your motors, double it and check to be sure it is less than what the L293D can handle. If it is not, you gotta stick with series.
V1 and V2 (and everything else) can be found here. NOTE --V2 also goes to the output pins (where the servos go) so just be aware of this.
Series/parallel
Your motors are in series if you hook the positive of one to the positive point on the driver board and then the negative of that motor to the positive of the next. Followed by, the negative lead of the second motor going to the negative connection on your driver board. Christmas lights may or may not be a good image for series depending on whether or not when one burns out the whole strand is dark, series, or when one burns out you can see that it needs replaced, parallel.
Your motors are in parallel if you hook both positive leads to the driver’s positive connection and both negative leads to the negative connection. Best image for parallel is a ladder with the rungs being your motors/load and the sides/legs being your power rails. BTW, I mentioned Christmas lights above. Newer sets typically use parallel connections for the lights so when one burns out the whole strand doesn’t go dark. Only the dead one is dark.
Read Frits’ post Picaxe 28
Read Frits’ post Picaxe 28 Project Board for Dummies. It will tell you all you need to know about V1 and V2, plus everything else about that board. It is a great reference.
Oh, and yes. If you run the motors in series, each gets half the voltage that they would have gotten singly or in parallel. So they will run much slower and with less power. Since you are starting at 4.8V, and you lose 1.5V through the motor driver to begin with, you are starting with 3.3V. Now divide that in half. Will your motors run at 1.45V? Maybe not so well.
everyones so helpfull
ignoblegnome: just check fritz link an collected ,very helpfull link.
birdmun:thank you for the brackdown on parallel an series, my motors are conected in parallel that was very easy discription to follow .
chris the carpenter:
2 motors at the rear as follows
2 motors at front as follows,
Front has in parallel 240mA(2x120mA) at 6v
how would i work out the rear motors in parallel data for the states 40-230mA at 12v
hope your not getting tired of my dumb questions
cheers
OK, I see a couple of
OK, I see a couple of problems with this.
Maybe you’ll be able to deal with item #1, but #2 is a deal breaker.
motors
hi ignoblegnome
sorry my mistake
1 yes same motors diferent vendors,
2 your right i have conected them in parallel on each side not fron an rear.
rushing when typing an not thinking sorry
OK. With luck you actually
OK. With luck you actually have 4 identical motors. You should be good to go!
Time to jump in
Ok, time to jump in.
We can talk about math all day long. At this point, hook up each side in parallel. Hook up each “set” of motors to the motor driver. Put the robot up on books so the wheels can turn freely. Run the darn thing.
Put your finger on the motor driver chip and let it spin. If it gets hot, come back and tell us --If it just gets a little warm, forget about everything we talked about in this thread and go build robots.
You may want to expand this test by dragging your finger along one (or more) of the wheels --Introduce a “load” and see if we start getting hot then.
No hot = good.
Little Hot = Probably ok
Hot = still probably ok (but we may want to talk about heat sinks
Too hot to touch = STOP and Unplug
