Most mains transformers hum to some extent. And most of the time, there is no problem for me.
But occasionally, some of my electrical appliances “buzz” dramatically louder than normal. My first guess is that it’s just a peak loading issue, but my observations below don’t entirely correlate to that. I’ve gone months without this happening, but, more recently, it’s been happening 2-3 times a week.
So any ideas of what kind of loading/noise/distortion may be causing this? Also, what differentiates the transformer design of the appliances which are more susceptible?
Here are my notes so far:
1.It affects just my plasma screen in the living room, microwave in the kitchen and clock/radio in the bedroom, each on a different ring main, connected to the common distribution box for the incoming mains.
2.Each of these appliances has an above average hum all the time, but occasionally, the problem starts and stops like an on/off switch: From gentle hum to irritating buzz in an instant. When I notice it on one of the three appliances, it is always present on the other two. When the buzz problem is occurring, it remains there, in reduced volume, even when the appliance is in standby mode.
3.My Plasma screen is connected via a Belkin filter/suppressor strip, which has no affect on the buzz. When I added my high end Audience capacitor-based power conditioner in series, it had no affect on the buzz. In fact, the conditioner itself buzzes very quietly under these conditions, even though it is purely passive, with no transformers that I’m aware of. It’s usually 100% silent. I've read that regenerators, like the PS Audio PPP, may help, but I don't want to go down that particular path.
4.My mains voltage typically fluctuates between around 233 and 242 volts. There is a limited correlation between voltage and time of day, but absolutely no correlation between voltage and the buzz.
5.It is more likely to happen in the evenings, but that could be because that’s when I’m most likely to be watching TV. Of the times I’ve been around at the start and stop times, there’s nothing consistent with the timing, but when the buzz does start, it often, not always, lasts for most of the evening. There’s no difference between weekends and week days.
6.I live in a small village, miles from any city or industrial area.
But occasionally, some of my electrical appliances “buzz” dramatically louder than normal. My first guess is that it’s just a peak loading issue, but my observations below don’t entirely correlate to that. I’ve gone months without this happening, but, more recently, it’s been happening 2-3 times a week.
So any ideas of what kind of loading/noise/distortion may be causing this? Also, what differentiates the transformer design of the appliances which are more susceptible?
Here are my notes so far:
1.It affects just my plasma screen in the living room, microwave in the kitchen and clock/radio in the bedroom, each on a different ring main, connected to the common distribution box for the incoming mains.
2.Each of these appliances has an above average hum all the time, but occasionally, the problem starts and stops like an on/off switch: From gentle hum to irritating buzz in an instant. When I notice it on one of the three appliances, it is always present on the other two. When the buzz problem is occurring, it remains there, in reduced volume, even when the appliance is in standby mode.
3.My Plasma screen is connected via a Belkin filter/suppressor strip, which has no affect on the buzz. When I added my high end Audience capacitor-based power conditioner in series, it had no affect on the buzz. In fact, the conditioner itself buzzes very quietly under these conditions, even though it is purely passive, with no transformers that I’m aware of. It’s usually 100% silent. I've read that regenerators, like the PS Audio PPP, may help, but I don't want to go down that particular path.
4.My mains voltage typically fluctuates between around 233 and 242 volts. There is a limited correlation between voltage and time of day, but absolutely no correlation between voltage and the buzz.
5.It is more likely to happen in the evenings, but that could be because that’s when I’m most likely to be watching TV. Of the times I’ve been around at the start and stop times, there’s nothing consistent with the timing, but when the buzz does start, it often, not always, lasts for most of the evening. There’s no difference between weekends and week days.
6.I live in a small village, miles from any city or industrial area.
) Maybe the source of the noise is from a neighbours appliance. Think of items with large motors in them. Vacuums, Fans, etc.
