is L293D diffrent from a H_Bridge?? or PCB ones!

hi im making a sweet robot soon and i see both h-brdiges dual channel and... and L293D isL293D just a dip like version??? or it misses /have more features then h-bridges!

the h-bridges im talking about are L298N ,
L298,L6203

It is.
The 293D has built in diodes so you can leave those out of your pcb design.
But you really need to read datasheets to understand differences between chips.
One thing to know is the maximum current for a L293D, which is 0.6 A.
The L293 (without D, so without diodes) can handle 1 A.
That current is the main difference between a 293 and a 298, besides their footprints.

Once you’ve sized and located appropriate motors, then you’ll be able to choose a suitable
H-bridge - first work out the mechanics (speed / torque / gearing), then find a motor / gearmotor, and only then think about the driver.

Pololu have a wide range of cheap H-bridges and is good place to look if you need more
than the L293/L298 style drivers can manage. The L293D and L298 are not suitable for
low voltage systems (6V) as they are darlington drivers and lose many volts. In general
MOSFET bridges are superior, but cost more.

in iran its not like you chose beetween models and go find on stores its like this ou go to store and make list of all and make a choice :smiley: but thanks so much i dont have multimeter so i can't see my motors stats !!!! i use gearbox that uses 1 motors and rotates 2 wheels eachside !!! i can post pic if interested!

kamhagh:
in iran its not like you chose beetween models and go find on stores its like this ou go to store and make list of all and make a choice :smiley: but thanks so much

You may not have such a wide range of choice or be able to find such (or purchase) online in Iran - but that doesn't mean you should ignore what MarkT wrote. You should size things first, then fit the driver to what you have found for size, otherwise you are just operating blindly, and will likely spend more money burning through parts than you would have otherwise.

Even if your choices are limited to a subset of available h-bridge IC designs (and old ones at that - though I don't discount them entirely, as long as you understand what they were originally designed for - and that is for systems in general operating between 12 and 24 volts - typically older automotive designs) - you should still have the information about what you need for the design before you purchase parts.

At least then - if none of the available IC h-bridges will suit you - you can decide to build a discrete component h-bridge (which isn't generally recommended - but in your case may be necessary).

kamhagh:
i dont have multimeter so i can't see my motors stats !!!!

Then you should beg, borrow, steal or build one before you go further.

In fact, building your own multimeter will teach you more about electronic design and function than just about any other project; you'll gain a ton of knowledge on the subject, and have a great tool to help you move forward with your projects. You could build such a device using discrete components (likely with an analog meter movement), or you could build it using an Arduino (or likely, in the finished version, a "standalone arduino" circuit).

Note that whatever you do build likely won't be very accurate (without being able to compare the results with a high-accuracy commercial meter) - but it will be better than nothing; one hint: Whether you decide to go with a discrete component design, or use an Arduino, choose any external components (resistors and such) to have as small of a tolerance as you can purchase and afford (for instance, in a balanced Wheatstone bridge of a discrete component analog design, you want your known resistances to be 1% tolerance or less; preferably much less). You also want to use quality construction techniques for the final implementation - they more accurate the parts you use and the more quality and accurate your construction, the more accurate the final meter will be.

kamhagh:
i use gearbox that uses 1 motors and rotates 2 wheels eachside !!! i can post pic if interested!

You can do that, and it may help us somewhat to help you select a proper h-bridge, but even so it will still likely only be a guess, because manufacturers can construct motors that look identical on the surface, but have wildly differing electrical specifications, depending on what application they were originally designed for. Even so, it couldn't hurt - but you should really try to obtain a multimeter of some sort (if you can't afford one, look into splitting up the cost with a group of like-minded friends, perhaps - start an "electronics club" or similar - your own "hackerspace" in Iran, if you will).

kamhagh:
i dont have multimeter so i can't see my motors stats !!!! i use gearbox that uses 1 motors and rotates 2 wheels eachside !!! i can post pic if interested!

OK. Stop here.

You should get a multimeter before "guessing" about the components and their ratings - it's a waste of your and our time, for you to keep guessing. Building with electronics without a multimeter (any kind will do, even a $10 one) is just stupid.

// Per.

ok thanks !!! i will buy one no matter how expensive then !! my fathers paying for it but !! i will somehow buy it !! searching net for good multimeters / how to chose :slight_smile:

website i order my stuff on doens't ahve multimeter im searching on other websites!!

any of these good?

DT-9205M best (guess the brand is named best!)

DT-830D

MT87

A830L

i can afford all they're cheap !!

EDIT: NVM im going to store my self !! the prices are so wired !!! its 3x times cheaper than amazon price !

i bought a multimeter ! alittle expensive :slight_smile: but how should i see amps for my motor? just make my multimeter act like wire and see amps while motor is runnign?

how to use l293d? i saw tutorials on net but not information !

kamhagh:
how to use l293d? i saw tutorials on net but not information !

// Per.

i made it work nvm ! seeing my motors amp anyway
i didnt know i can share both GNDs to one rail!