SparkFun Forums

[stone]

Hello,

I'd like to add a RPM sensor and display
to a 110 vac, house current, single phase, miter saw.

The sensor is finished and working fine,
but it is powered by a battery.

Is there a way to tap into the 110vac in a small way
to get my 5vdc power?

I know I could use a wall-wart sized, transformer
power supply. But is there anything smaller?
Thanks.

[jremington]

A transformer is a safe source. Look for a small one (plentiful and cheap at recycling or thrift stores).

[lyndon]

If you're going to say "is there anything smaller" you need to say smaller than what. Give dimensions; wall warts come in all sizes.

[stone]

I decided to try this power supply. I also ordered the 5v version too.
This is pretty small and I should be able to tuck it in somewhere.

IRM-02-3.3
Manufacturer: Mean Well
Input Voltage: 85 VAC to 305 VAC, 120 VDC to 430 VDC
Output Voltage: 3.3 V
Output Current: 600 mA

Length: 33.7 mm
Width: 22.2 mm
Height: 15 mm

I’m not sure if this is enough power.
But everything is an experiment for me anyway.

Thanks.

[lyndon]

https://www.aliexpress.com/item/New-Han ... .99.jbmDWN