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Ideas to consume less current with less heat

Posted: Sat Dec 07, 2019 12:37 am
by bonadio
Hello

I have a project where I have to use a 12V power supply to power a wroom module in active mode with BT (not deep-sleep or light sleep), the problem is that my voltage regulator (UTC1117AL 3.3V Dpack) gets really hot.

I was able to reduce some current consumption running at 80Mhz, now my module consumes 50-60mA and the regulator is not very hot but still hotter than I need. I am trying to stay away from a switching regulator and heat sink because my board is very small and I want something simpler.

I think if I could get at 35-45mA the regulator would be ok. I dont need cpu performance nor BT range (1-2meters just fine)

Any ideas on what I could do to minimize current consumption?

Thanks

Re: Ideas to consume less current with less heat

Posted: Sat Dec 07, 2019 4:11 am
by ESP_Sprite
Any chance you can use a buck converter? Wasting 9V in general is a bit of a shame.

Re: Ideas to consume less current with less heat

Posted: Sat Dec 07, 2019 4:28 am
by bonadio
Hi ESP_Sprite

That would be my last option for two reasons, one is space with buck convertes I will need an inductor which takes lots of space and the second is interference, in my early prototypes I used a buck converter with an inductor and when I started using NVS (with Preferences library to store some values) for some reason my board started to freeze everyday when I turned on for the first time, when I switched from it to a Linear regulator the freeze was solved. So I really dont feel comfortable with it.

One option that I am considering is using a buck to convert from 12 to 5 (I need 5V too) and a Linear to convert from 5 to 3V

But before that I would like to make sure that there is no other option on the side of the ESP

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Re: Ideas to consume less current with less heat

Posted: Sat Dec 07, 2019 5:12 am
by username
I know your looking to reduce power from the ESP32, But realistically the main issue is that your using a linear reg where your should be using a switching reg. We use this in audio products without any issues so i'm sure it will be ok for your use.

This is for people who want to solder by hand.
https://www.digikey.com/products/en?key ... F1.5-W12-C

We now use this one for everything.
https://www.digikey.com/product-detail/ ... ND/4499516

Re: Ideas to consume less current with less heat

Posted: Sun Dec 08, 2019 12:03 am
by bonadio
Hi username

Thanks for the links I will check on that.

But I still want to dig on the Esp side, this blog
http://iot-bits.com/ultra-low-power-des ... 2-10-tips/

on Item 6 he says that I can write to the DPORT register and turn off the peripherals that I dont use, this seems like an interesting thing to investigate.

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Re: Ideas to consume less current with less heat

Posted: Sun Dec 08, 2019 12:06 am
by username
@bonadio, I understand, no problem.

Re: Ideas to consume less current with less heat

Posted: Mon Dec 09, 2019 3:01 pm
by bonadio
HI

Just to complete my finds, I discovered that there is a register that controls the peripherals
DPORT_PERIP_CLK_EN_REG
reading from it I found that most of the peripherals when not used are off so seems that the module are already configured for minimum power consumption.

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