# emonTX using AC power and load from pulse counting and CTs?

**URL:** <https://community.openenergymonitor.org/t/emontx-using-ac-power-and-load-from-pulse-counting-and-cts/320>\
**Category:** Hardware\
**Tags:** ac, emontx\
**Created:** [10 May 2016 11:08 UTC](https://community.openenergymonitor.org/t/emontx-using-ac-power-and-load-from-pulse-counting-and-cts/320 "2016-05-10T11:08:13Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![peter](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/peter/32/2749_2.png) [@peter](https://community.openenergymonitor.org/u/peter)\
**Post date:** [10 May 2016 11:08 UTC](https://community.openenergymonitor.org/t/emontx-using-ac-power-and-load-from-pulse-counting-and-cts/320/1 "2016-05-10T11:08:13Z")

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Bit of extra clarification here please; I was reading up on things and saw the text about using the emonTX on AC and not loading beyond 20mA. It mentions up to 4 temp sensors being OK. I am however using one optical pulse counter and 3 CTs - should I move to USB power for better accuracy, not knowing quite how much that will affect things given the pulse counter says is consumes 5.3mA during a pulse and none without - the CTs don’t use power do they?

This is from [EmonTx V3 - OpenEnergyMonitor Wiki](https://wiki.openenergymonitor.org/index.php/EmonTx_V3#Power_Supply_Options)

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**Author:** ![Robert.Wall](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/robert.wall/32/38246_2.png) [@Robert.Wall](https://community.openenergymonitor.org/u/Robert.Wall)\
**Post date:** [10 May 2016 11:56 UTC](https://community.openenergymonitor.org/t/emontx-using-ac-power-and-load-from-pulse-counting-and-cts/320/2 "2016-05-10T11:56:49Z")

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My simulation shows that that should be OK.