Cigarette lighter to outlet adapter creates noise?

I bought an adapter that plugs in the cigarette lighter and provides 2 electrical outlets. This one: (amazon associate link to inverter removed by admin)

Now unfortunately, whenever this is plugged in, even with nothing plugged into the outlets (!), the microphone input on my laptop gets a bunch of white noise that won't go away until I unplug the thing from the cigarette lighter. Obviously I have a mix plugged in and intend to use it.

Maybe this unit is a cheap unshielded one? Is it possible to buy a similar product that doesn't have this side effect? It's unusable for me as is.

Any advice would be great!
-Brian

Just try another brand/model. I've been installing a dual USB, panel mount, charge port and recently had one that made noise. Just that one. All the others have been noise free. Still not sure why that particular one made noise

Web

I had a couple of low power ones that did that and I tried a better/higher output one that is rated for an IPad and it works great.

Not sure if you guys looked at the link, but it was a 110V inverter that he is plugging in - presumably not in his plane (since you would not hear white noise in the plane).

sj

The same advice applies with any type of power supply/port. Swapping them out is the easiest way to deal with the noise. Circuits that change voltages are particularly prone to making noise and cheap stuff is even worse.

As for being a 110 VAC power supply, remember that lots of the new systems have download and programing capabilities that are accessed with a laptop. Maybe he needed power for that laptop?

Web

wireweinie said:

The same advice applies with any type of power supply/port. Swapping them out is the easiest way to deal with the noise. Circuits that change voltages are particularly prone to making noise and cheap stuff is even worse.

As for being a 110 VAC power supply, remember that lots of the new systems have download and programing capabilities that are accessed with a laptop. Maybe he needed power for that laptop?

Web

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Yeah, I needed power for the laptop. So....all the adapters like this that I see seem like they change voltage. Does that mean it's likely that *any* adapter that plugs into cigarette lighter and provides a 3-prong electrical outlet is going to make noise? I'm only seeing cheap ones on Amazon. Is there a better website to buy this sort of thing? Price doesn't matter, quality does.

Thanks for the responses.

An option would be to find one with a power cord. Connect it to power and place the converter on the floor boards or in the back seat. If the converter makes noise, separation by distance is useful.

Your battery in the laptop won't hold for say an hour or so?

Web

wireweinie said:

An option would be to find one with a power cord. Connect it to power and place the converter on the floor boards or in the back seat. If the converter makes noise, separation by distance is useful.

Your battery in the laptop won't hold for say an hour or so?

Web

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Yeah, it's about an hour. Thanks, I'll try to put the cord down on the floorboards and see if it's better. If not, try a more expensive one if I can find one.

You need a converter that will sit on the floor or in the back. The converter itself is what is making the noise, not the cord. That's why it needs to have a long power cord and not plug directly into the lighter socket.

Web

Most laptops are 18vdc. Easier to step up from 12vdc to 18vdc. I would not run an inverter...especially a random amamazon buy in my airplane....on the ground or in the air.

Tim

Can you run a battery pack for your computer? You'd need to recharge it but there would be no noise.

Web

wireweinie said:

Can you run a battery pack for your computer? You'd need to recharge it but there would be no noise.

Web

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thats what I use... can go 24 hours on a charge....

https://www.hypershop.com for my mac

behindpropellers said:

Most laptops are 18vdc. Easier to step up from 12vdc to 18vdc. I would not run an inverter...especially a random amamazon buy in my airplane....on the ground or in the air.

Tim

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I've had lots of them overheat and agree with Tim on this. Plus they are usually pretty high amps, are they not?

sj

SJ said:

I've had lots of them overheat and agree with Tim on this. Plus they are usually pretty high amps, are they not?

sj

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Yep... My lenovo power supply is 20VDC @ 200W = 11.5 A pulling about 2A on your inverter.

Going DC->AC inverter->AC to DC power supply really makes no sense.

Also keep in mind that USB C has several voltage/amperage modes - all USB C supplies are not the same.

If you really need (really really need) to charge your computer via aircraft power you might want to seek out an engineered solution.

Tim

Many electronic devices require sine wave inverters. Cheap ones usually don't provide that. Cigar plug inverters aren't much good for anything.

Depends on the load, modified sine wave (non pure sine wave) small inverters are perfectly adequate for many loads. BUT, for sensitive electronics, pure sine wave is preferred. SAMLEX is one maker of inexpensive (relative) sine wave inverters.

I had a Canadian outfit (whose name escapes me right now) that has supplied oddball converters for off grid types for decades, when i want to charge my ebike battery inflight. It's 52 VDC nominal, 58.2 at a full charge. The Rotax has a limited amount of electrical power, and i did the numbers and figured I could charge at about two amps (at 50+ volts) which would draw about 8 or 10 amps from the plane system. I explained exactly what I wanted, and for less then $200.00 they custom built me a nice little unit with a lighted rocker switch, and auto shut off when the plane voltage falls below a certain threshold, plus a high limit, so no way can I over charge. Idiot proof in other words, all mounted in a aluminum box about the size of a large cell phone.

I have a 120 VAC charger I use at home to charge the bike battery, but by the time I inverted up and down, it was a grossly inefficient way to do it. I notice no radio interference BTW. I carry the batteries in a aluminum belly pod, and they are quality Panasonic cells with a quality battery management system, before someone says I'm crazy to do this! 1 hour flying while charging, gives me another 5 to 9 miles range on the bike, and it is a mountain bike with a lot of power, but I digress! I can post the outfit's name and address if someone wants it.

stewartb said:

Many electronic devices require sine wave inverters. Cheap ones usually don't provide that. Cigar plug inverters aren't much good for anything.

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We run some pretty big PA systems on pontoons here on the lake. Some folks have gone direct off of cheap generators and alternators and burned up some nice equipment. Honda makes a couple that put out sine wave, but I always put a power conditioner in the circuit, or use an actual UPS (where the device runs of battery, and the power recharges the battery) as this cleans it up pretty nice. Square waves will eat computers and electronics like an angry bear...

sj

Jerotas said:

Yeah, it's about an hour. Thanks, I'll try to put the cord down on the floorboards and see if it's better. If not, try a more expensive one if I can find one.

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Would you not be better off to buy a new good quality battery for the computer that should last the duration you need?
This would cost less and be safer than rigging inverter.

Having had more than one inverter let out smoke, I sure would not want that to happen when flying.

OLDCROWE said:

I had a couple of low power ones that did that and I tried a better/higher output one that is rated for an IPad and it works great.

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What particular better brand you got?