I have been having a lot of trouble with my L293D and I haven’t gotten an answer that hasn’t been telling me that my L293D is ancient and unreliable. I already know, but I can’t get anything else and this is all I have so please don’t answer like that. I’m was using a 9V battery which worked 1/10 times initial I found out that it is a smoke alarm battery and that isn’t suitable for motors. I then switched to 4 1.2 V AA rechargeable batteries but my multimeter said they were outputting 7 amps of current and it still didn’t even work. The L293D shield’s LED would flicker for like a millisecond every 2 seconds as well as not powering the motors. Then I tried 4 non-rechargeable 1.5 V batteries the exact same way as my other batteries and my multimeter read 2 amps. This has made me lose any grip of knowledge on electricity I had. Also did I mention the exact same thing happened? I also tried the Mac power supply and that worked 10/10 times except it has to be connected to a Mac and all the motors ran really really slowly. I have no idea how to fix any of these problems and I am getting angry as all forums just tell people to go get some other thing because of the inefficiency of the L293D. My circuit is just the L293D on top of the Arduino Uno with 4 motors at M1, M2, M3 and M4 and a connection from the batteries in the power input of the L293D. Also I would like to use the rechargeable batteries as they were $6 each because they were 2 amps so if possible, please make the main power source. Thanks in advance!
No idea what you are trying to proove with this statement.
Same deal here.
Draw a schematic of your circuit, pencil and paper is ok.
Include all devices used and whatever power supply.
Also any code you are using along with which Arduino etc etc.
Using the L293 You should calculate the driver uses 2 - 4 volt. Then add the voltage You wish for the motor. The sum of driver voltage and motor voltage is what the power supply needs to provide.
So you can't handle the truth?
I am sorry but unless you are prepared to to give that chip at least 12V and possibly 24V then because they are very inefficient the chip eats up so much voltage there is not going to be enough left to turn the motors.
Tell me that you didn't put the meter into current mode and put the leads directly across the battery?
If you did that is not a way of testing a battery but destroying it. Current measurements must be made with the meter in series with a battery load.
It still didn't work because you were not supplying enough voltage. The current capability was fine but the voltage was too low.
So they have a voltage of 1.2V therefore you need to use about 12 of them in series to supply enough voltage. Assuming that is that your four motors will run on only 2 Amps.
This is the exact thing circuit I’m using, just imagine twice as many batteries. I can also easily handle the truth but I have no way to use anything else and must avoid the truth.
Which is still only 6v, or 4.8v if they are NiCads (i.e. 1.2v rechargeables). The L293 requires a higher supply voltage because it uses Darlington pairs of bipolar transistors. Its design dates from probably the 1960s and I doubt that it is even made any more. So if you must use the L293, buy more rechargeable batteries or treat yourself to a bench power supply that can handle probably at least 10A to supply the motor stall current.
My motors are (I think, I got them I while ago) just 600 mA 3V-6V dc motors. I haven’t actually used a multimeter before and I just started learning how so I just put the red banana wire into 10 A and the black banana wire in COM and put it onto the negative and positive sides. I recently learned that is how to short circuit things. It did show me a 2 amps on a 2 amp battery so I thought that’s how it worked. The circuit is in a comment above.
Yes, as you were told in your other post on this same topic.
Is the L298 a good driver or is it very similar?
No, it is every bit as bad as the L293D. Those chips are around 30 years old. And they require fairly high motor supply voltages (minimum 8V) to work at all. So, of course 4x1.2V AA batteries won't work.
When you try and drive your motors, what does the battery voltage drop too?
Not seeing your code, when you program the motors to run, how fast are you commanding?
255 in PWM.
If so measure the voltage across your motors to see how much they are receiving.
To add code please click this link;
Thanks.. Tom....
PS. I'm at work at the moment, so may not be able to get back for a few hours.
My code just turns all the DC motors at once for 20 seconds and then turns them off. I know it works as when connecting it to 24 volts (my laptop), they all go on, but very slowly. I’m commanding them to go at 255. Will the HG7881 work (I’m asking this questions as I seem to not be able to identify an inefficient and ancient IC)?
