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DC Motor supply voltage 6v from 3v3

dman

Sep 17, 2020
4
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Sep 17, 2020
Messages
4
Hi everyone,

I am working on a project where I want to drive a 6v motor from a 3v3 lithium battery. The motor is going to be driven using the DRV8838 driver which can take 0-11v but my motor is only 6v.

The motor will be driven only for couple of seconds, up to 4 seconds maximum, but it could draw up to 1.8A at 6V. I've looked at op-amps, but I don't think they can provide required current.

Could anyone guide me what/how I should go about this?
 

Alec_t

Jul 7, 2015
3,587
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Jul 7, 2015
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3,587
Welcome to EP!
You need a DC-to-DC boost converter with a suitable spec. Loads advertised on the web.
 

bertus

Moderator
Nov 8, 2019
3,307
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Nov 8, 2019
Messages
3,307
Hello,

On the page of the circuit is stated that the maximum output current is 100 mA.
You said that you need about 1.6 A for the motor.

Bertus
 

dman

Sep 17, 2020
4
Joined
Sep 17, 2020
Messages
4
I've done Googling. Came across a really neat Power Designed by TI. I've entered by Input/Output parameters and it just gave me a circuit a BOM and a Simulation. Neat, never seen this before. I am going to try and whisk this $4 circuit together and see if works.

upload_2020-9-17_21-36-15.png

upload_2020-9-17_21-36-55.png
 

dave9

Mar 5, 2017
1,188
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Mar 5, 2017
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1,188
Heh... "$4 circuit". If you already have the spare parts and want to build it yourself that is an option, but if you have to order parts, you can get approximately 3 components delivered for $4 (unless it's a chinese supplier so it's taking the month-long slow boat from China) and still need to *build* a PCB.

I'd recommend just getting a ready made module. Amazon doesn't have the selection that some do but the shipping is fast, for example these:
https://www.amazon.com/Honbay-Step-up-Module-XL6009-Converter/dp/B07KBRWWQX/

If you can wait a month, these XL6009 or others are cheaper, around $1 each or less in bulk from ebay or various Chinese electronics suppliers like banggood or Aliexpress, etc.

Does the motor need a particular performance level? A typical 6VDC brushed motor will still operate at 3.3V with reduced performance of course, so it would be slower but in some cases acceptable if it still has enough torque.
 

dman

Sep 17, 2020
4
Joined
Sep 17, 2020
Messages
4
Yeah sorry the $4 is only for the BOM cost, obviously manufacture of an actual working DCDC Boost would cost much much. I am a little torn between buying ready made kits because for my project I have extremely small space to work with. I am afraid that I could prove the concept but then would not able to package it. When I say extreme, we are talking less than 500mm2 for DCDC Boost, MCU, connectors, and all of the other components. Thank you for the link though, if all fails I'll definitely have to resort to ready made boards.
 
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