powering an esp32ue dev board,

[joel gerardi]

I have a esp32ue dev kit on a breakout board I need to control 4 relays.  The relay board i am using has a 115 to 5vDC  transformer on it.  (https://www.amazon.com/dp/B077YLQ6DL?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_19)

When i use this to power the esp32, and set the configuration as follows i get extremely erratic behavior. It works fine, then just starts clicking and then resets the tasmota back to its defaults.  I have tried many different configurations and it is always the same result.

If i power the esp with usb using the same configuration as above, and use a relay board that has no transformer, all works fine.

I am running two relays with one gpio because it will be controlling a two pole circut.

I would like to use and onboard transformer as it makes the enite hookup simpler for me.

Can anyone help me out with what is happening here?

I would like to 

[Bart van Seters]

A transformer converts AC to AC.

You need a powersupply input 115V and output 5V DC

Op zo 17 mei 2026, 18:37 schreef joel gerardi <joelg...@gmail.com>:

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[joel gerardi]

I stand corrected.  This 4 channel relay i am trying to use has an onboard power supply.   Input is 115v AC, output is 5v DC

[Philip Knowles]

It sounds like the power supply is not powerful enough. There are a lot of reviews on Amazon saying that you can't turn on more than 2 relays at once.The power supply looks to be a 700mA one. The relays draw 185mA - 740mA if all 4 are on. I'd get a 1A 5VDC supply 

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From: sonof...@googlegroups.com <sonof...@googlegroups.com> on behalf of joel gerardi <joelg...@gmail.com>
Sent: Sunday, May 17, 2026 21:34
To: TasmotaUsers <sonof...@googlegroups.com>
Subject: Re: powering an esp32ue dev board,

To view this discussion, visit https://groups.google.com/d/msgid/sonoffusers/33e5bced-129e-44fc-8569-9ecb0f6a34b2n%40googlegroups.com.