Before you say it - 'because their bored' yes very good but I beat you to it!
Seriously though Ive noticed it with some pieces of equipment in this case its a Hi-Fi. Even though its off NOT on standby, but properly off - you can still hear a hum.
It is still on at the socket but other devices don’t do this. Is it bad design electronically or is there a reason some devices do this?
2007-07-31 22:00:48 · 10 answers · asked by Richard 3 in Consumer Electronics ➔ Other - Electronics
your Hi-Fi has a remote.
in order to allow it to turn the system on/off, the system has to have power to the remote circuitry.
It is also an older system, because it uses a linear power supply with a transformer - which is the thing that hums.
now if the above isn't true, unplug the unit and find the thing that IS humming.
2007-08-01 03:28:05 · answer #1 · answered by Bill R 7 · 1⤊ 0⤋
To be honest, you've either got dodgy mains in your house, or you are using poor quality kit.
Nothing should 'hum' if switched off at the mains. Decent quality electronics won't even hum on standby. Poor quality gear will hum all the time...
2007-08-01 01:54:23 · answer #2 · answered by Nightworks 7 · 0⤊ 1⤋
This is because there is a transformer in most electronic devices which creates a buzzing noise which is then amplified by the appliance.
2007-08-01 03:50:03 · answer #3 · answered by Anonymous · 0⤊ 1⤋
They are still using power, hence the humm.
If you turn it off at the mains, does it humm? Doubtful, unless there are large capacitors that keep power to the system.
Many electrical systems keep using power to let the system get turned on quicker. Some use as much power as they do when they are turned on. It keeps your electric bills high.
2007-07-31 22:08:02 · answer #4 · answered by whatotherway 7 · 1⤊ 1⤋
Most electronic appliances contain transformers, which do hum!
2007-08-01 06:26:39 · answer #5 · answered by Anonymous · 0⤊ 1⤋
It's because they contain transformers (not the changing vehicle robot type!).
If the ON/OFF switch is on the secondary (which is theoretically safer as it wouldn't be mains voltage at the switch) then there is still mains going to the transformer.
2007-07-31 22:09:54 · answer #6 · answered by ? 7 · 1⤊ 1⤋
It could be a problem with the device not being earthed properly??
2007-07-31 22:06:31 · answer #7 · answered by toppershouse 1 · 1⤊ 1⤋
i had this the other day humming on my pc speakers,so i unscrewed the plug tightened up the earth/live/neutral
and it stopped humming
2007-07-31 22:18:35 · answer #8 · answered by Anonymous · 1⤊ 1⤋
It could be they are on standby and are feedbacking from other appliances or electrical fields
2007-07-31 22:03:51 · answer #9 · answered by superliftboy 4 · 1⤊ 1⤋
Actually, they hum because they don't know the words.
2007-07-31 22:09:02 · answer #10 · answered by Anonymous · 0⤊ 2⤋