Small inverter 12v current draw?

[chewi]

I prefer a genny
The point was more that these days there's less and less need for an inverter onboard, thankfully lots of smaller electronics stuff charges from usb now plus ebay has a multitude of dc buck/boost converters available for any oddities.



Don't suspect, it's true




I went over to Xlr's quite a while ago, a fair bit of work and the price adds up, but they are just streets ahead of those horrible ciggy lighters.

Good to hear I'm not alone in my move to XLR..

I'm not joining in with the argument about inverters/converters! There's no mileage in it for anyone.


As to the efficiency, while I am certainly convinced a DCDC converter can and should be more efficient than an inverter, It isn't necessarily so for a given device. If any were really efficient I think they would advertise that.

Cheap electronics can be very inefficient, e.g. a TV or monitor on standby should consume almost nothing, (just enough to respond to the controls), but typically they sit in instant readiness unnecessarily consuming almost as much as when they are in use.

 

[nigelmercier]

To get above 12 volts, from a 12 volt source ... you will need some form of an 'inverter'.
I'm sure the packaging will call it a converter (which employs an inverter), as it is an easier term to grasp for the less tech savvy members of the buying public...

...I was not calling a DC -DC converter an inverter...

Really.

Trip, trap, trip, trap!

 

[Happy Dayz]

Yes, lets.

You said

I replied

You then made several posts claiming that my convertor was/is/contained an inverter.

Plain fact is, you misunderstood the difference and misunderstood how to get more than 12v DC from a 12v DC supply.

My posts were not rude by any stretch of the imagination.

OMG Aunt -

Paul, Please re-read the o/p's opening post, the bit in brackets at the very bottom especially! "Converters are not the issue".

But you chime in about your converter - so why? Who says the o/p wants to only power low voltage devices?

I did not start in about converters, inverters, were the subject in the headline and the route I stayed on track until inane chat about converters.

You posted two links, look at the components list regarding 'inductor' wth do you think a transformer functions as? It simply proves it is in truth a later form an inverter - so do you get it now?

It goes on to say inductors are used for filtering which is another common use for them, they would tend have only 2 wires, which some call them chokes, but let's not go there ��






I do not dwel in that world, but accurately said you may still require an inverter - meaning they might need to run mains voltage equipment such as a mains drill, mains vacuum cleaner. Grinder, multi tool, food blender whatever that won't run on your beloved low voltage output 'converter'.

You want/can run low voltage kit there are various options available but that was quite clearly stated as not the questions subject was it! The O/P specifics were clearly asked about inverters - savvy yet?

So it is not plain fact as you put it, I misunderstand or misunderstood nothing, leaving that to you.

No boasting or bragging, this is to show my validity.

My working background is in electronics servicing and installations of alarms, cameras access control, CCTv and many other types of kit. I've run my own 'one man band' firm for past 30 odd years with no advertising, no bankruptcy not even a ccj.

Guess I must get something right, if you think how many recessions I've been through.

With no formal electronic qualifications, time to time by those who know me, I'm used as their 'go to guy' problem solver, either they can't resolve a fault .problem or need to design around it, trust me I'm do not work cheaply to call in.

But I would like to know how without some form of inverter circuit used, the principle of how 12 volts can be increased at a really useful voltage and current, another thread perhaps though ��

I did not specifically say or mention your posts, strong debate is a big part of forums and enjoyed.

I mentioned the disrespectful remark about a bridge and digging, that poster knows exactly who they are. I can't give it or them the credence to bother looking back for it.

I'm sincerely sorry to you for any misunderstanding - and proving I will oppologise when I think I'm even possibly wrong.

Alan


Not everyone has rechargeable tools as example.

 

[Happy Dayz]

Really.

Trip, trap, trip, trap!

Your remark is very obtuse, shows to my opinion you do not understand written English - ideally for you perhaps you might work in a call centre for a double glazing or PPI company?

For the technically more challenged.

an inverter converts DC To AC Typically (while not technically limited to) 240 vac.

Technically it can be designed to any reasonable AC output voltage example 150 vac as used for building site tools, it follows to your hearts desire, if designed to and you care to pay for that.

where a converter does what it says on the tin I.e. DC - (typically 12 volts), to a DC (usually lower than 12 volts).

Those 'converters' that deliver higher voltages than the Input, use some form of inverter, where old inverters used a very lumpy transformer, as confirmed by the components in the Wikipedia Link now use a an inductor with a capacitor and an electronic astable (2 transistors) instead of a buzzer - but it is STILL an inverter circuit to produce the higher voltage, then converted to DC output - do you now savvy?

If you still can't comprehend that, its not my problem to educate you any further.

Alan

 

[pelissima]

Here some numbers for my case.
Old LenovoT61 in need for 19V, using a Belkin 300W inverter is milking 4Amps –same as fridge. Mind you, the Belkin unless engine was on, was buzzing in need for more power. But this symptom stopped when I rewired the 12V input directly in the Belkin discarding the sig plug. Through similar thread last year I learned of DC to DC and ordered one from ebay. I was expecting a consumption around 2 Amps plus and imagine my frustration when I metered above 6 Amps. So it is back to Belkin for me at least for laptop.

 

[nigelmercier]

... but it is STILL an inverter circuit to produce the higher voltage, then converted to DC output ...

So we are back to converters do have inverters in them now?

Except they don't, what you are describing is a charge pump.

 

[[164147]]

That all depends on the type of converter - the cheaper low-power DC converters are solid state so don't have an 'inverter'.

 

[Happy Dayz]

So we are back to converters do have inverters in them now?

Except they don't, what you are describing is a charge pump.

Time Out Guys-:
I'm not going into voltage pumps.

O/Ps Thread askes about inverters, not converters, not watering cans or flowers but inverters, later states very clearly she understands about converters and so is not interested.

I assume the O/p has already been down that road and found for ehat ever reasoon a converter is not for her. That blows out all the discussion about them.

The whole nub of this extra debate was brought about my simple advice in my earliest post 'you might still need an inverter'.

So what dose the O/P get? Dozens if post about converters ?

That advice is totally fair, these little 'converters' as some of you seem must call them, simply do not deliver enough current to drive the more power hungry devices many people still need desire to use.

advice is given about choping into laptop cables - really? Thats really safe not knowing how any person might acheive that?

People may well not need that high power for their needs and a low power voltage pump might suit them, the good reason i did not say 'you must have one' at the time.

Personally, i have a 2kw inverter, i don't have a need for a 'converter' of sny type or to know exacty how cheapy very low power 'converters' work, especially to get to a higher voltage. I have much if that bought in hope discarded as junk.

Personally i would not touch them with a bargepole suspecting fire safety issues.

i've put forward how they could acheive by using a (modern) form of inverter circuit - and staying on track.

I'm done and leaving it there, we will all just have to agree to disagree if you don't agree, because if i agreed - we would all be wrong ? .

 

[nigelmercier]

... The whole nub of this extra debate was brought about my simple advice in my earliest post 'you might still need an inverter'...

It was "you might still need an inverter ... to get above 12 volts" that kicked it off, but I agree it is best left.

 

[rogerthebodger]

It was "you might still need an inverter ... to get above 12 volts" that kicked it off, but I agree it is best left.

Nigel I think it is the difference between design engineers and installation "engineers" (technicians) that is causing the different view points.

I have seen that particularly in my mechanical design career but also in my electrical and digital electronics design career.

 

[Lon nan Gruagach]

Both inverters and converters use the same principle of induction through magnetic fields to provide different voltage characteristics.

Unless its a charge pump.

 

[rogerthebodger]

Unless its a charge pump.

I use lots of small boost buck converters to regulate the 11 to 14 VDC boat power to a regulated 12VDC for voltage sensitive equipment including simple LED lights.

I have also made 18vdc NiCad battery drill charger with a boost buck converters and current limiting resistor.

http://www.learnabout-electronics.org/PSU/psu33.php

I only use a mains inverter to power drills of my wet/dry vacuum cleaner.

 

[Happy Dayz]

It was "you might still need an inverter ... to get above 12 volts" that kicked it off, but I agree it is best left.

I still think the wording is perfectly fine as is, using the 'might' I did not dictate or offer any upper voltage limitation, so, I can see no fault.

I think this a forum not a lawyers course in diction, dictation in persuance of total accuracy. If nothing else please allow us senior citizens a little latitude, before we are reduced to peeing our pants, chasing nurses with intent but with no lead for completing the mission through lack of fire power, just dribbling into our kidney bowls about days and conquests long gone by ��.

Alan

 

[Lon nan Gruagach]

I'm pondering buying a small inverter for charging/running various low power items from the boat's 12v supply*, but getting a bit confused about the likely current draw.

There are a couple of makes commonly sold as '150w' (which would probably do me) supplied with a cigarette lighter plug on them. IIRC 150w @ 12v = 12.5A. (I'm ignoring losses 12v to 230v.) Surely one wouldn't want to be pulling anything like 12.5A from a cigarette lighter socket?

Am I misunderstanding something?

(*Yes, I know there are DC converters, etc. That's not the issue here.)

Bringing it all back....
You would have to search for the manufacturer's claim about efficiency. Modern, small, cheap ones arent going to be too bad depending on load. Not just the power the load takes, but its power factor. Lights and heaters are nice, well behaved loads that dont cause trouble, drills. and the like are a right royal pain for this conversation.
Since there are just too many unpublished factors your best bet is just to suck it and see (with an ammeter naturally).

As for what to do if you dont want to use cigarette lighter plugs...
Neutrik XLR X series are rated at 16A and not really suitable for harsh environments (I wouldnt even think of another make btw). If you really want to use connectors (hard wired would be my preferred option) then high current battery connectors are the way to go, specialist marine versions hopefully being designed for exposure to salt.

 

[Happy Dayz]

Nigel I think it is the difference between design engineers and installation "engineers" (technicians) that is causing the different view points.

I have seen that particularly in my mechanical design career but also in my electrical and digital electronics design career.

I've spent a lot if time installing and servicing security kit.

you can get two excellent engineers to fit systems from the same spec sheet to identical houses, will wire them out and program differently.

Same go's for fault finding, both will have a good success rate but fail on some systems, one turns up at a previously visited by the other guy fault, and fixes it due to his different approach. It's weird that he might also do that within seconds of walking in, where the first engineer misses on all those extra calls.

Alan

 

[rogerthebodger]

I've spent a lot if time installing and servicing security kit.

you can get two excellent engineers to fit systems from the same spec sheet to identical houses, will wire them out and program differently.

Same go's for fault finding, both will have a good success rate but fail on some systems, one turns up at a previously visited by the other guy fault, and fixes it due to his different approach. It's weird that he might also do that within seconds of walking in, where the first engineer misses on all those extra calls.

Alan

Sorry but I think your use of the term of "Engineer" for some one who "installs and services security kit" is not the correct term .

You are a "Technician" an Engineer is a different animal all together.

I do agree the give and Engineer of Technical the same problem or design brief and they will come up with different but acceptable solutions/designs.

 

[Happy Dayz]

Sorry but I think your use of the term of "Engineer" for some one who "installs and services security kit" is not the correct term .

You are a "Technician" an Engineer is a different animal all together.

I do agree the give and Engineer of Technical the same problem or design brief and they will come up with different but acceptable solutions/designs.

After over 45 years in my trade, i think i can call my compatriots and myself what i like .

Earlier alarm installation engineers used to make the whole lot on site by hand from sheet materials, controls, contacts, coils and formers for relays. They were beautifuly made with pride, right down to the chassis and varnished wooden cover boxes.

Funny thing is in my trade engineers feel they can call themselve technicians before they can even read a meter.

Fortunately, i can operate as either and can design right down to, and produce at pcb level.

i like to say an engineer is paid for what he does, where as a technician is paid for what he thinks the engineer dose - but is often completely ignored.

An engineer will use a hammer after first having his breakfast, a technician will direct it - after doing his emails first.

Alan

 

[rogerthebodger]

After over 45 years in my trade, i think i can call my compatriots and myself what i like .

Earlier alarm installation engineers used to make the whole lot on site by hand from sheet materials, controls, contacts, coils and formers for relays. They were beautifuly made with pride, right down to the chassis and varnished wooden cover boxes.

Funny thing is in my trade engineers feel they can call themselve technicians before they can even read a meter.

Fortunately, i can operate as either and can design right down to, and produce at pcb level.

i like to say an engineer is paid for what he does, where as a technician is paid for what he thinks the engineer dose - but is often completely ignored.

An engineer will use a hammer after first having his breakfast, a technician will direct it - after doing his emails first.

Alan

I think you have a twisted view of what an Engineer is and his level of training, qualifications and more importantly his professional responsibility.

An Engineer gets paid for what he knows a Technician get paid for what he does.

Have a look here as to what a "Engineer" is.

https://en.wikipedia.org/wiki/Chartered_Engineer_(UK)

 

[Happy Dayz]

I think you have a twisted view of what an Engineer is and his level of training, qualifications and more importantly his professional responsibility.

An Engineer gets paid for what he knows a Technician get paid for what he does.

Have a look here as to what a "Engineer" is.

https://en.wikipedia.org/wiki/Chartered_Engineer_(UK)

Well Roger,
Years on call outs, dealing with deranged customer and fixing system I'm definitely weird and of a split personality but I've never claimed to a charted engineer that you link refers to.

Think you just kicked yourself in the but while only having one leg ;(

Something an engineer would likely avoid through common sense and a knowledge of gravity, while a technician would try to design around it on his iPad while looking to blame some one else.

Alan

 

[rogerthebodger]

Well Roger,
Years on call outs, dealing with deranged customer and fixing system I'm definitely weird and of a split personality but I've never claimed to a charted engineer that you link refers to.

Think you just kicked yourself in the but while only having one leg ;(

Something an engineer would likely avoid through common sense and a knowledge of gravity, while a technician would try to design around it on his iPad while looking to blame some one else.

Alan

Well myself with 5 year Engineering apprenticeship, night school a technical college. The degree in Mechanical Engineering followed after several years experience mainly mechanical design mid 1970's elected M I MechE and therefore CEng. Moved into industrial machinery control system design including PLC's and then Micro controller hardware and software design. The into application software design lats 25 years before retiring as just got tired of call outs, dealing with deranged customer and fixing system and trying to get employees to do the job I pay then for.

IMHO Engineers and Technicians are different kinds of people and as in my case I have been on both sides of the fence but this is not always the case as of course common sense died a long time ago as there we have it.

Just a point out, term CEng was instituted by the various bodies representing various Engineering professions to distinguish between technicians calling then selves engineers and those who have gone through extensive theoretical, practical training and practised their profession for a number of years and have attained a high level of expertise together with legal responsibility for the work they perform.