This is me watching TV. I assume with a pattern like this, sense will never be able to detect my amp and TV. As the picture changes, the TV is constantly fluctuating in power to adjust the power to the LEDs. Same goes with the sound amp, it is constantly changing to adjust for the power of the sound required by the show.
Has anyone else had sense detect their tv or sound system.
I’m fine with it not being able to detect either one. I’m not asking for miracles, I’m just curious if sense can use the other properties of the power signal to determine that this is my TV and sound system.
First, Sense primarily does on-detections and off-detections based on a single short (sub-1 second) transitions. Devices that have internal power supplies, like most consumer electronics, are difficult to detect for a couple of reasons. DC power flowing to the active electronic device is somewhat decoupled from the the AC power flowing into the the power supply, both in terms of time and magnitude. Part of the reason is simply due to the power conversion itself - AC RMS power comes in 1/120 of a second bursts (see below), while DC power is continuous. Most power supplies use energy storage elements like capacitors and inductors to convert the periodic power into stable lower-voltage DC power. That energy storage and voltage difference really delays and distorts the demand from the actual DC device from the power waveform (current) it actually pulls from the supply.
If that weren’t difficult enough, things like TVs and stereos have operating power that fluctuates depending on the content, the type of device audio/visual/mixed plus even the format (LCD/LED TV - subtractive vs. OLED TV - additive).
Sense does use techniques beyond short-transition identification. If your TV is a networked smart TV and falls into a relatively small subset of Samsungs or LGs, it might get detected based on it’s network traffic (on/off) via NDI. But I wouldn’t count on that.
You can also employ a TP-Link/Kasa smart plug if your TV or AV receive chew up a lot of power - Sense supplements its detection with information from specific power sensing smart plugs. I use a TP-Link 300 in my AV cabinet to watch my Yamaha AV Receiver and Sony TV.
Finally, and this is pure speculation, I believe that each time Sense labels a transition in the Power Meter, those transitions are the ones the Sense monitor sends back to the mothership for identification. Seems like your TV and amp kick out a lot of good-sized transitions. My Sony LCD and Yamaha really only use about 200W each, and the transitions associated with them in the on mode are typically in the neighborhood of 5 W rather than 12W to 132W. Wondering if you have a plasma TV ? I’m wondering if the volume of transitions stemming from your TV and amp might make your home challenging for Sense to detect other devices… Plasma TVs are know to be “noisy” for Sense and can affect identification.
Here’s my ancient Sony 65" LED in action (via smartplug)
Wow. Thank you for the detailed response. When I first heard of this product, it seemed like black magic. I have to admit, it’s still pretty amazing to me. Thank you for the education.
I have a TV and a receiver plugged in to a APC h15 surge protector/ line conditioner. Instead of hoping to accurately detect them I just plugged the APC h15 into a smartplug linked to Sense
