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Power supply?

PostPosted: Wed Nov 19, 2014 5:55 pm
by ghostwheel
I was thinking how to power the device.
First, for a small temperature sensor, that I'd like to power with a battery.
I found things like this:
http://www.ebay.com/itm/DC-DC-0-8V-3V-to-3-3V-1A-Switching-Voltage-Regulator-Step-Up-Boost-Power-Supply-/231062865700
Do I need this? Or can I just power it off a CR2032?
Then I thought to use it for smart light bulbs, so I'd need a small AC/DC convertor. Something like this:
http://www.ebay.com/itm/3-3V-600mA-AC-DC-Power-Supply-Buck-Converter-Step-Down-Module-/371064464466
What do you usually use?

Re: Power supply?

PostPosted: Thu Nov 20, 2014 8:19 am
by Sjaak
Aw that dc/dc convertor looks very bad assembled, look at the solderjoints. Also I don't think it can steady supply the advertized 1A with just 1 AA(A)battery.

AFAIK the eps8266 uses max 350mA at 3V3 when transmitting, so in theory it can work. Be sure to put lots of decoupling caps in the design. If you want to try please post your findings.

A CR2032 can no way power this thing. IIRC it can supply only a few mAs.

I wouldn't recomment that AC/DC convertor too as it doesn't look safe (no (visible) galvanic isolation for example) and has no housing.

How about a just plug adapter? I just picked on of the first hitt on ebay but just for the idea: http://www.ebay.com/itm/Global-AC-100V- ... 51b8f4c6fe

All the nasty ac stuff is in the plug :D

Re: Power supply?

PostPosted: Thu Nov 20, 2014 9:39 am
by Michaelo
For bench work you could bang together a small supply using LD1117V33 (3.3 volt @ 1.5 Amps), throw in a couple of 100uF caps and your there for less than $5...
To power the unit use any good quality DC source between 5 and 15 volts...

Optionally you could pick up one of these: http://www.electrodragon.com/product/br ... er-module/

For actual real-world application I'm going with a rechargeable but haven't decided on which one yet... ideas gratefully received ;)

Re: Power supply?

PostPosted: Thu Nov 20, 2014 9:50 am
by alonewolfx2
have you tried LD1117V33 ? i tried ams1117 3v3 its good but idle power conumption 3-4ma without esp.

Michaelo wrote:For bench work you could bang together a small supply using LD1117V33 (3.3 volt @ 1.5 Amps), throw in a couple of 100uF caps and your there for less than $5...
To power the unit use any good quality DC source between 5 and 15 volts...

Optionally you could pick up one of these: http://www.electrodragon.com/product/br ... er-module/

For actual real-world application I'm going with a rechargeable but haven't decided on which one yet... ideas gratefully received ;)