L293 in parallel

[moonstreat]

Hi,

I wonder if I can do this:

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is that if I mount the outputs in parallel will have twice the power?

what do you think? this works?

 

[Ubergeek63]

it is not generally a good idea since the piece of crap is has bipolar outputs and they do not share current well if not forced with series resistors. That said at least they are on the same silicon so if one is hogging the current it the other will be heating up at the same rate.

0.2 ohm in series with each output driver should be enough, all you need is enough to wash out the differences in saturation voltage and when one takes more current to push the excess over to the other driver.

 

[moonstreat]

You can post a circuit with such resistance that you recorded?

 

[Hero999]

I don't think there will be any need for current sharing resistors because, going from another thread, the motor he's powering only uses 700mA which is only slightly above the maximum rating.

The sense resistors will also probably help to current share.

Both halves of the L293 need to be connected in parallel, the outputs and inputs both connected together.

Here's a schematic.

 

[moonstreat]

this is with the L293E .. I need to l293B

 

[Hero999]

It's the same principle, connect the inputs and outputs on either side of the h-bridge together.

The L293B is the same as the L293E but without sense 1, 2, 3 and 4.

Look at the datasheet
https://www.st.com/stonline/books/pdf/docs/1328.pdf