[porousshield]

I recently bought a new adapter for my laptop after the old one broke. The problem is that it makes a constant erratic clicking noise and also hums when it's plugged into the computer. Once it's unplugged the noise stops. I rechecked the serial number and it's supposed to by the adapter for my laptop . Do I have to worry about this thing catching fire or is it just something some adapters do?

I've been sitting here for the past five minutes with the adapter up to my ear so I guess my colleagues think I'm retarded now.

[zibber]

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[RBM]

Originally Posted by porousshield To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

I recently bought a new adapter for my laptop after the old one broke. The problem is that it makes a constant erratic clicking noise and also hums when it's plugged into the computer. Once it's unplugged the noise stops. I rechecked the serial number and it's supposed to by the adapter for my laptop . Do I have to worry about this thing catching fire or is it just something some adapters do? I've been sitting here for the past five minutes with the adapter up to my ear so I guess my colleagues think I'm retarded now.

When I think of 'clicking' noises, i envision either moving parts or expansion/contraction of material to the extent that sound is emitted.

Last I knew there were no moving parts in an adapter for a laptop. After all an AC to DC adapter is primarily two coils of wire with different physical attributes that will accomplish the task of converting voltage/currents.

Hold it in your hand while it's clicking and see if you can feel the material expanding/contracting ?

[Photolysis]

Adapters having some level of humming is not something to be concerned about by itself, but without hearing it for myself it's hard to say if it sounds suspicious.

Is the clicking noise definitely coming from the adapter itself, and not from the power supply where the adapter connects to your laptop? Either way, it sounds like something you would want to get fixed.

	Originally Posted by RBM To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Last I knew there were no moving parts in an adapter for a laptop

It's possible that it has a fan, though this should be obvious by the vents, or lack thereof.

[porousshield]

Thanks for the responses.

I left the computer running all night and now the adapter stopped ticking and now it just hums. I've shaken it and there doesn't seem to be loose parts inside and the noise definitely wasn't coming from my laptop. I've tried some different outlets and I can't reproduce the noise so maybe it was just from being new? Maybe?

[bobabrowncoat]

I've run into this problem in houses with old wiring and in areas where the power was unreliable. It's also possible that something else on the same electrical breaker might cause it like a refrigerator or stove.

As for why it's doing it, not all power adapters are made equal. It might have a different tolerance to dirty power.

[porousshield]

	Originally Posted by bobabrowncoat To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	I've run into this problem in houses with old wiring and in areas where the power was unreliable. It's also possible that something else on the same electrical breaker might cause it like a refrigerator or stove. As for why it's doing it, not all power adapters are made equal. It might have a different tolerance to dirty power.

I just noticed that it's one particular plug-in that it ticks with and this is an old building so it's probably the wiring. My other plug-in it doesn't make any noise.

[RBM]

Originally Posted by Photolysis To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

Adapters having some level of humming is not something to be concerned about by itself, but without hearing it for myself it's hard to say if it sounds suspicious. Is the clicking noise definitely coming from the adapter itself, and not from the power supply where the adapter connects to your laptop? Either way, it sounds like something you would want to get fixed. It's possible that it has a fan, though this should be obvious by the vents, or lack thereof.

All the adapter's I've seen have been passive devices. A fan would actually be sort of a good idea, though.

---------- Post added 07-30-2012 at 04:33 PM ----------

	Originally Posted by bobabrowncoat To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	I've run into this problem in houses with old wiring and in areas where the power was unreliable. It's also possible that something else on the same electrical breaker might cause it like a refrigerator or stove. As for why it's doing it, not all power adapters are made equal. It might have a different tolerance to dirty power.

What exactly is the component that would 'click' because of 'dirty power' ? 'R', 'C', 'L' - or chip ?

Refrigerators have compressors which are a relatively high amp device. What does a stove have in that sort of way ?

[Kisai]

Originally Posted by porousshield To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

I recently bought a new adapter for my laptop after the old one broke. The problem is that it makes a constant erratic clicking noise and also hums when it's plugged into the computer. Once it's unplugged the noise stops. I rechecked the serial number and it's supposed to by the adapter for my laptop . Do I have to worry about this thing catching fire or is it just something some adapters do? I've been sitting here for the past five minutes with the adapter up to my ear so I guess my colleagues think I'm retarded now.

You have a relay in your AC adaptor, a physical magnetic switch that functions to change the number of coils used in the step transformer. Its there because your AC adaptor can handle American 60 Hz AC and the 50 Hz used in other parts of the world. That clicking you hear is the relay going back and forth.

I wouldn't use it. Every time the relay switches, there's a small current spike that goes to your laptop.

	Originally Posted by RBM
	What exactly is the component that would 'click' because of 'dirty power' ? 'R', 'C', 'L' - or chip ?

This is known as 'talking out of your ass'. None of these components make clicking noises because none of these components have moving parts. Circuit breakers also use relays.

[Bioplasmoid]

The clicking could also be momentary electrical arcing. I wonder, has the OP has tried attaching a pocket multimeter to the DC output, and checked the voltage level? Is it fluctuating massively?

[Kisai]

	Originally Posted by Bioplasmoid To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	The clicking could also be momentary electrical arcing. I wonder, has the OP has tried attaching a pocket multimeter to the DC output, and checked the voltage level? Is it fluctuating massively?

If it was arcing, it would be melting the plastic, and the OP would notice the magic smoke.

[Photolysis]

	Originally Posted by RBM To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	All the adapter's I've seen have been passive devices. A fan would actually be sort of a good idea, though.

They do exist, but I suspect that they are probably rare for laptop adapters. My 240W brick doesn't have one, and that's pretty much as high as laptop power requirements go.

[Bioplasmoid]

	Originally Posted by Kisai To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	If it was arcing, it would be melting the plastic, and the OP would notice the magic smoke.

That depends on how much arcing there was. I used the word momentary for a reason. I can't see it melting the plastic unless it was continuous. Besides I was under the impression most of the plastics used in these types of devices are picked for their thermal safety characteristics,among other factors.

[porousshield]

Originally Posted by Kisai To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

You have a relay in your AC adaptor, a physical magnetic switch that functions to change the number of coils used in the step transformer. Its there because your AC adaptor can handle American 60 Hz AC and the 50 Hz used in other parts of the world. That clicking you hear is the relay going back and forth. I wouldn't use it. Every time the relay switches, there's a small current spike that goes to your laptop.

That doesn't sound good. It only clicks on this particular plugin though and clicks more when I plug it in for the first time. It's a pain the the butt because I'll have to order another one in because there's none around town.

[RBM]

	Originally Posted by Kisai
	This is known as 'talking out of your ass'. None of these components make clicking noises because none of these components have moving parts. Circuit breakers also use relays.

Hehehe, that was precisely the point Mr. Kisai. No dry humor for you, eh ?

Breakers ? My oh my, what is the world else could use relays ??

Semi-seriously to add to your irrelevant thing on breakers, here's my irrelevant thing - you ever see one made ? I have.

	Originally Posted by Kisai
	You have a relay in your AC adaptor, a physical magnetic switch that functions to change the number of coils used in the step transformer. Its there because your AC adaptor can handle American 60 Hz AC and the 50 Hz used in other parts of the world. That clicking you hear is the relay going back and forth.

Got an link ? Cause I KNOW you wouldn't talk 'out your ass', right ?

[Kisai]

	Got an link ?

I don't need a link because I actually have a brain and not a search engine for a substitute. Go do your own homework and if you're going to ask a question, don't make it a stupid one that can answer itself by 5 seconds of thinking.

	That depends on how much arcing there was. I used the word momentary for a reason. I can't see it melting the plastic unless it was continuous. Besides I was under the impression most of the plastics used in these types of devices are picked for their thermal safety characteristics,among other factors.

I'm considering this as a possibility. The dielectric breakdown voltage of air is 3 megavolts/ meter and for plastic its exceeds this by 3-5 times? (I'm not sure but its definitely greater than air..) Dielectric breakdown means that the molecular structure of the material cannot maintain cohesion in the electric field. For a thermally insulated plastic, it would indicate such high voltages that the corresponding power (V^2/R) would also be terribly high and would melt the plastic.

[HackerX]

Here:
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Cheap components in these equals excess noise (both in terms of audible and electronic due to poor filtering of the output).

[bobabrowncoat]

	Originally Posted by porousshield To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	That doesn't sound good. It only clicks on this particular plugin though and clicks more when I plug it in for the first time. It's a pain the the butt because I'll have to order another one in because there's none around town.

Have you checked that outlet to see if it's wired correctly? Do you have a landlord that takes care of that? I'm more inclined to think the problem is with the outlet than the power adapter.

Like I said before, not all power adapters are created equal. I've gotten two from the same company that used different parts before.

[RBM]

	Originally Posted by HackerX To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.
	Here: To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts. Cheap components in these equals excess noise (both in terms of audible and electronic due to poor filtering of the output).

Thanks HackerX, but we aren't talking about that.

Kisai's claim is the relay used in a laptop adapter to switch between 50 cycle or 60 cycle outlet power. That's the adapter I want to see.

Google is a veritable haystack when looking up laptop AC adapters.

[porousshield]

Thanks for the help everyone. It's calmed by fears of burning to death in the night.

It's a pain to get another adapter so I'm just going to leave the thing plugged into the plugin that it doesn't make any noises with. It's an old lappy anyway so if something happens it'll just give me an excuse to buy a new one.

I got another question, the adapter has a blue light that stays on even when it's plugged in to neither the laptop nor AC, so how does that work? Stays lit for quite a while too.

[HackerX]

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Also interesting, when I was doing ma' research, this blog came up explaining these things and perhaps justifying why arcing might be occuring.


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. He talks about a USB charger, but it's all the same. It's an interesting read if you want to know what goes on inside a power adapter.

[RBM]

Originally Posted by HackerX To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts.

To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts. Also interesting, when I was doing ma' research, this blog came up explaining these things and perhaps justifying why arcing might be occuring. To view links or images in this forum your post count must be 2 or greater. You currently have 0 posts. . He talks about a USB charger, but it's all the same. It's an interesting read if you want to know what goes on inside a power adapter.

That's a good link to get into the nitty-gritty of the electronics of today with some comments of what was done historically in the way of circuitry.

Here's the first clue that no relay is used in this phone application, to switch between 50 and 60 Hz, emphasized:.

	The charger is labeled "FOR iphone4. Input 110-240V 50/60Hz Output 5.2V 1000mA, Made in China."

Later, the second clue, in the 'Notes and References' is related information to the switching power supply, HackerX posted:

[1] Switching power supplies often take a "universal" input of 110V to 240V at 50/60 Hz, which allows the same supply to conveniently work on worldwide voltages. Because a switching power supply chops up the input into variable slices, the output voltage can be independent of the input voltage over a wide range. (This also makes switching power supplies more resistant to power brownouts.) Of course, designing the circuit to handle a wide voltage range is harder, especially for power supplies that must be very efficient across a wide range of voltages. To simplify the design of early PC power supplies, they often used a switch to select 120V or 240V input. Through a very clever doubler circuit, this switch converted the input bridge into a voltage doubler for 120V input, so the rest of the circuit could be designed for a single voltage. Modern power supplies, however, are usually designed to handle the whole voltage range which both avoids the expense of an extra switch, and ensures that users don't put the switch in the wrong position and destroy something.

[Kisai]

	users don't put the switch in the wrong position and destroy something.

They are talking about a physical, user-manipulated switch on the older power supplies, not a relay.

	Input 110-240V 50/60Hz

Let's use our brains for 5 seconds, shall we?

To step up or down voltage we need a?

( Show Spoiler )

transformer

And the physical part of the transformer to change the voltage/amperes depends on its

( Show Spoiler )

number of coils in the primary vs. number of coils in the secondary

and to change the above, if you don't want to use two different

( Show Spoiler )

transformers

you would change the

( Show Spoiler )

tap/connection to the number of coils in the primary that you want

And to do that you would need a

( Show Spoiler )

switch to change the tap to the number of coils you use

and if you want to make it automatic, you'd make a

( Show Spoiler )

relay

to internalize the

( Show Spoiler )

operation of the switch

so stupid users don't accidently fry their computers.

And finally, the clicking is caused by a physical friction, which means a moving part, and the only moving part used in 99%[1] of the electronics[2] used today is the relay.

[1] My MEMS class was cancelled.. BOO! But touchscreens use variable capacitators in their screens to tell what you're pressing. I would count this as a moving part as well.

[2] I don't count motors as a component of electronics, but an electrical workhorse.

[JackCY]

They all make noise because of the electronics inside, but unless it's quiet - night you should not hear it. If you hear some loud crap from it, it's poor quality or your power in the house is a mess. There may be just one part, don't know the English name now, that causes this, same stuff as in other electronics.

Try it at a different house if it makes noticeable noise and if it does, get it exchanged.