how can I disable auto-standby on TV soundbar? - Page 1
Forum section: electronics / beginners

author: Andaho
author_rank: Newbie
timestamp: October 10, 2015, 02:55:56 pm
content: I just bought a Philips HTL2101A/05 soundbar, but have discovered a really annoying feature that is built into ALL soundbars sold in the EU... After a period of inactivity, to meet EU regulations, they have to automatically switch off.This is annoying because I don't want to have to press 2 power buttons when I turn the TV on... I have the soundbar connected via the headphone socket on the TV, so I control the volume with the TV remote. I want the soundbar to just stay on! - surely it doesn't use much power when there isn't any sound being played anyway?When googling for this problem/feature, there are lots of people complaining about the auto-standby. My particular model states that it goes into standby after 15 minutes of no sound and no buttons on the remote being pressed (there are no buttons on the soundbar itself). The other really annoying "feature" it has, is every time it goes into standby, it resets the volume - so apart from having to turn it back on, I have to turn the volume back up every time I turn it on.I was first thinking along the lines of having some kind of IR transmitter, automatically sending the volume up command every X minutes (since I have it set to max anyway, and use the TV to control the volume) - but I have no idea how I would do this... so then I was thinking along the lines of how to generate a slight noise on one of the inputs to prevent standby? - or what about a voltage being sent to the digital coaxial input? - or how about shorting out a circuit inside the soundbar?There must be some kind of "hack" to prevent it going into standby? - perhaps one that could be universally used to prevent any soundbar going into standby?Does anyone know how I can do this... or can anyone point me in the right direction of how I might be able to achieve this?Thanks.

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 10, 2015, 04:23:14 pm
content: There are several projects for popular microcontrollers (Arduino, et.al.) which will generate IR signals.Is the soundbar gadget reacting to SPECIFIC IR codes, or simply to ANY kind of IR signal?You could test it with an IR remote from some other appliance and see if it keeps the soundbar awake.If it is just reacting to the presence of ANY IR signal, you could make a very simple and cheap circuit with an IR LED and a 555 timer chip to send an IR pulse every 10 minutes, etc.

author: Andaho
author_rank: Newbie
timestamp: October 10, 2015, 04:45:17 pm
content: Thanks Richard,No, it's not any IR, it needs to be one of the remote's codes... I'm aware of the Arduino projects for acting as a universal remote... but buying an Arduino especially for this purpose seems a bit overkill... in my searching I also came across methods of using a mobile and an IR led on the headphone socket, and WAV files that send the command... but again, it seems a bit overkill for the job :SI do like the idea of a chip more advanced than the 555 chip, that I could program with the code... but I have no idea what chip you can program like that, or how to program it :S - nor do I have anything to read the codes sent from remotes... I was thinking that there would be an android app that can read them - since a camera can pick up the IR - I expected to be able to find an app to tell you what the code is... but I haven't been able to find anything. EDIT/UPDATE - having looked at a remote's IR flash through my mobile's camera, I can see why there isn't an app for it - it's far too fast for the camera to capture!I am very much a beginner... but eager to learn... I don't like the idea of using an Arduino for it, just because it's so overkill for the purpose... not because of the cost, but just because it's overkill... and I'd like to learn how to do it at it's most simple... but having said that, if there's an easier way to accomplish this task (other than simulating the IR), that would be cool too... I'm thinking along the lines of something like a high-pitched tone generator (that humans can't hear), that I could plug inbetween the TV and the soundbar to simulate a constant sound - thus preventing it from going into standby?

author: Andaho
author_rank: Newbie
timestamp: October 10, 2015, 11:24:29 pm
content: After doing a little more research, I think a simple solution of programming an old universal remote with the 'volume up' button, and having a simple 555 timer 'push' the button every ~10 minutes would be a perfect solution...I'm struggling to find a guide on how to make this kind of circuit... would I have to use a relay to 'simulate' pushing of the button on the remote? - I assume I can just connect wires to the contacts of the button I want pressed?

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 11, 2015, 12:06:25 am
content: You can probably use a FET transistor across the desired button. When you put voltage on the gate of the FET, it will conduct and simulate a button push.You will need to interconnect the ground of your 555 "finger simulator" circuit to the ground bus of the remote control.But if your scheme raises the sound level by one "click" every 10 minutes, won't the volume be at "full blast" when you go to turn it on tomorrow?

author: Andaho
author_rank: Newbie
timestamp: October 11, 2015, 12:11:34 am
content: The volume being max isn't a problem, because I want the soundbar at full volume - because I control the volume with the TV. Thanks for your advice.. I continue my research and looking into FET transistors now

author: Jope
author_rank: Regular Contributor
timestamp: October 11, 2015, 02:15:59 am
content: Quote from: Andaho on October 10, 2015, 04:45:17 pmI can tell you what I would use: an ATtiny microcontroller acting as a remote. To receive IR signals from the original remote you need a IR receiver IC like a TSOP38238 (they come in multiple varieties:http://www.vishay.com/ir-receiver-modules/).I you want to go the route of pressing a button on a universal remote: for this purpose I would use a 4066 analog switch IC (controlled by an ATtiny).

author: German_EE
author_rank: Super Contributor
timestamp: October 11, 2015, 02:54:21 pm
content: There has got to be a connection at some point from the L&R audio inputs to the CPU so that the audio can be detected and the timeout counter reset. Find this point (a scope is all you need) and then feed an audio pulse in there every five minutes or so.

author: PTR_1275
author_rank: Frequent Contributor
timestamp: October 11, 2015, 03:24:11 pm
content: Would another way of "seeing" the original remotes signal be to connect a scope to the leads of the IR led on the remote? Single shot capture it and then work it out from there?In terms of the hardware, I can't issue any help sorry. My sub on the home theater turns on / off automatically based on input levels which gets annoying. It turns off after about 5 minutes but needs several seconds of signal to turn on. When watching a movie sometimes the sub will turn off then turn on halfway through a bassy scene. I might crack it open and have a look what is inside.

author: Jope
author_rank: Regular Contributor
timestamp: October 11, 2015, 03:54:42 pm
content: Quote from: PTR_1275 on October 11, 2015, 03:24:11 pmOf course, provided he has a scope. But I doubt that.

author: SeanB
author_rank: Super Contributor
timestamp: October 11, 2015, 04:18:00 pm
content: Open it up, and see where the audio goes to the MCU as a sense signal, then disconnect that and feed it some audio signal, probably simply mains hum from the transformer, fed via a 10n capacitor with a 47k series resistor, and that should fool it into staying on all the time.

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 11, 2015, 04:21:55 pm
content: Quote from: Jope on October 11, 2015, 03:54:42 pmYou don't need a scope. There are several publish projects that will "learn" the IR code (via an inexpensive IR receiver) and then reproduce the IR code on demand.

author: ez24
author_rank: Super Contributor
timestamp: October 11, 2015, 04:28:09 pm
content: Are there any universal remotes that can be programmed to send a signals based on set times?Seems there would be a market for such a device.

author: tec5c
author_rank: Frequent Contributor
timestamp: October 12, 2015, 02:13:37 am
content: Quote from: ez24 on October 11, 2015, 04:28:09 pmI would have thought so too, but a quick search turned up with no results.Would a simple 555 timer as a PWM connected to a button inside a universal remote not do the trick? If volume up is of no concern to you, a PWM signal to this button to simulate a press every X amount of seconds would suffice, no?

author: Chris C
author_rank: Frequent Contributor
timestamp: October 12, 2015, 08:37:56 am
content: I have a FM transmitter that would shut off after just a few seconds of silence. Very annoying.I tried mixing in a continuous ultrasonic signal. That kept it from turning off, without much amplitude. But it sometimes heterodyned with components of loud music, creating audible beat frequencies. A subsonic signal worked too, but required substantially more amplitude, which caused other artifacts. Several variations on these themes were tried, but I couldn't find anything that was 100% inaudible.Eventually I tried connecting every pin on the MCU to GND or VDD via a 10K resistor. Since providing an audio signal would turn it on, I quickly found the sense pin. It didn't even require a changing input, simply tying it to VDD through the resistor was sufficient.

author: Andaho
author_rank: Newbie
timestamp: October 12, 2015, 04:13:01 pm
content: Thanks for all the replies and suggestionsYeah, I do actually have a harmony 300 remote stashed away, and I'm aware that it can be programmed to turn on multiple devices with the power button, but the layout of the harmony isn't great for virgin media (a tivo box)... I have my tivo remote programmed to control the TV, so that's the only remote I use...Every time this stupid soundbar goes into standby, it 'resets' the volume to a 'normal' low volume... so it's not just the annoyance of having to turn it on with the TV, but also having to turn the volume back up - that takes more than a few seconds holding the volume up button.I've actually decided to pull apart the soundbar, and the TV... I've disconnected the TV speakers, and re-wired the TV straight to the soundbar speakers (so in effect, replaced the internal TV speakers with the soundbar speakers - not using the soundbar amp at all)... the max volume doesn't quite go as loud as before (which isn't a problem, because it's only for TV viewing), but it still sounds great...The only thing I'm a little worried about:Is it possible that these better speakers (from the soundbar) will be drawing too much from the TV amp? - or would that only happen if I turned the volume up too high? - or is it even possible to damage an amp by connecting more powerful speakers to it?... At the moment it's working (practically) as a perfect solution.

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 12, 2015, 05:27:28 pm
content: Yes, it is possible that the speakers in the sound bar are lower impedance than the internal speakers in the TV.So that makes the audio power amplifier chip inside the TV work harder, and raises the possibility that it could be burnt out.I would be rather wary of this "solution" for this concern. At least I would attempt to identify the audio power output amplifier chip inside the TV and monitor it for excessive temperature rise during operation.

author: SeanB
author_rank: Super Contributor
timestamp: October 12, 2015, 06:00:26 pm
content: No, the TV speakers will be 8R speakers, and the sound bar will be roughly the same. The audio amplifier in the TV will drive it without a problem, though if you listen at full volume you will probably overheat the TV amplifier, they are never cooled properly to handle that.So keep the volume below maximum.jusat look at the speakers on the TV set, and those in the sound bar. Probably both sets will be marked 8R, so will work.

author: peter-h
author_rank: Super Contributor
timestamp: October 16, 2024, 06:20:13 pm
content: Having been tearing my hair out with a Sharp HT-SBW202 sound bar over this absolutely stupid and irritating "feature" (dictated by Brussels, even though this thing draws barely a few watts), I think there are solutions1) analog audio to HDMI ARC conversion - the "ARC" feature may turn on the sound bar when sound is restored (but it isn't documented as such)2) analog audio to bluetooth conversion - on some, this will bring it out of standby3) analog audio all the way, and build a little circuit which injects say 100ms of 20kHz noise into the cable, every few mins - nobody will hear thatIf the sound is from a computer, it is easy e.g. thishttps://www.reddit.com/r/Soundbars/comments/nyxpzp/soundbar_standby_blocker_prevent_soundbar_from/orhttps://veg.by/en/projects/soundkeeper/

author: peter-h
author_rank: Super Contributor
timestamp: November 01, 2024, 04:31:24 pm
content: This circuit will inject 20kHz for 100ms every 5 mins into one of the two audio channels going to the soundbarI am not yet sure of the required level i.e. the value of the 100k resistor on the output.The two chips are CMOS 555s.

author: u666sa
author_rank: Frequent Contributor
timestamp: November 01, 2024, 09:47:57 pm
content: How about pulling the bin off the flash and trying to mess with it? You could disassemble it perhaps, or you could look for that period of inactivity in milliseconds.

author: peter-h
author_rank: Super Contributor
timestamp: November 05, 2024, 11:32:36 am
content: Unbelievably hard.BTW I think the above circuit could go inside the soundbar. The PSU there must be powered all the time, otherwise the remote would not work. Such a stupid regulation - so typical of BrusselsOtherwise, it should draw about 200uA so a PP3 should last almost a year.

author: peter-h
author_rank: Super Contributor
timestamp: December 01, 2024, 06:47:59 pm
content: Done it:This should work with any soundbar.In fact it should be possible to power it from the soundbar's internal power supply. This is always on, otherwise HDMI and other auto turn on features would not work. The auto shutdown is just a fake to comply with stupid Brussels regsOne could also replace the 1st 555 (which draws the 160uA) with a smarter low power timer, and extend the battery life to 5-10 years (they corrode anyway in that time).

author: Ian.M
author_rank: Super Contributor
timestamp: December 01, 2024, 08:17:41 pm
content: Sometimes an analog solution is not the best option. There's a lot of parts there to do a very simple job. If you've got *any* MCU programming experience, scrap everything to the left of the output filter and replace it with an ATtiny or similar low power low pin count eight bit MCU, programmed to sleep for approx. five minutes using its watchdog timer, then generate the tone burst and go back to sleep. It will also need a micropower LDO regulator to keep MCU Vcc stable as the battery ages, unless you can put it inside the soundbar and find a 5V standby rail to power it.

author: peter-h
author_rank: Super Contributor
timestamp: December 01, 2024, 08:54:58 pm
content: QuoteSee my sig for CPU typesActually it would takemuchlonger to do this in code. It took me about an hour to build this circuit.The ATTiny2313 (the replacement for the 90S1200 which I run in a number of products) would draw 20uA in sleep mode which is pretty good though. But it would be at least a day to get it done. If I was to sell this commercially (which may be viable due to the number of these stupic soundbars with auto shutoff - basically all of them except some are OK if used with an HDMI ARC TV) then yes I would probably do that, but it still needs to be programmed in production whereas the timer approach you just build...

author: Ian.M
author_rank: Super Contributor
timestamp: December 01, 2024, 09:15:41 pm
content: You are obviously an expert dead-bug/freeform prototyper, and I have no doubt that for *YOU* it was faster to prototype just with a soldering iron rather than switching to coding half way through. However many here are less good with an iron and would benefit from considering the MCU approach.

author: peter-h
author_rank: Super Contributor
timestamp: December 02, 2024, 07:44:42 am
content: It's call a "birdsnest" over hereIf you use a micro then you have to birdsnest that too, or use some sort of evaluation board, or design a PCB. And you still need to solder. It's going to take way longer.This is only a 100 quid soundbar...

author: Zero999
author_rank: Super Contributor
timestamp: December 02, 2024, 09:38:51 am
content: Quote from: peter-h on November 01, 2024, 04:31:24 pmWhy use two 555s? A single 556 will do.And why PWM the power to the second 555 when you can just PWM the reset pin?This circuit works at 40kHz, at a repetition rate of 100Hz, but you get the idea.555 burst.asc

author: peter-h
author_rank: Super Contributor
timestamp: December 02, 2024, 09:59:10 am
content: The idea is to not have any power on the 2nd 555, 99.999% of the time.Can't do that with a dual 555.

author: Zero999
author_rank: Super Contributor
timestamp: December 02, 2024, 05:50:53 pm
content: Quote from: peter-h on December 02, 2024, 09:59:10 amIf it's about low power consumption, then two oscillators made with the '4011 or 4001 quad NAND or NOR gate IC will use less power than two CMOS 555s.

author: peter-h
author_rank: Super Contributor
timestamp: December 02, 2024, 07:52:50 pm
content: That's true. And one could get into the nanoamp area with a circuit built with some discrete MOSFETs...But even better to put this inside the soundbar.