DC motor slowed by L293D or L293DNE

Projects General Guidance
1

Hi all,

I'm currently working on a project that involves controlling a 6VDC motor's speed and direction with my arduino uno. I'm using the L293DNE with 4xAA batteries but it seems to be slowing down my motor by about 20-30% compared to running it straight from the battery.
I have tested the output voltage of the chip and it doesn't seem like there is a significant drop.
None of the fixes I've found online have had an effect so I'm at a loss here.

Thanks in advance

2

The (ancient) L293 uses bipolar darlington transistors. They drop 2 to 4 volts depending on current. There is no way around that. More modern drivers use MOSFETs that drop much less of the supply voltage. Or use a higher supply voltage.

3

Why is it that i do not see a voltage drop then?