10watts for all 4, will it work

[dave_j_fan]

 As making basic EI transformer inverter is super easy  i am planning a thing

  i am adding a triac based switcher to make sure the apparent LED load is within 10W in the inverter
  so a bulb is made on at a time and fast switch is done so that every bulb look steady glow but inveter can be used is very low watt


 
   
  Experts please suggest will it work  ?

clarification :::
It is not a DIMMER
it is NOT a XMAS light
I dont want to use 12V LED

just DIY $5inverter should be able to do double duty that is 10W inverter drives 20W

[Zero999]

This seems like a bad idea.

Why not simply use 12V LEDs?

The AC is only converted back to DC inside the LEDs anyway, so it makes sense to use LEDs rated to the correct voltage in the first place.

[Twoflower]

I'm not sure if I understand your plan correct: You try to sequentially power one bulb or probably two  at the time, switch to the next and so on. Is my assumption correct?

In that case you'll probably run into problems. As the high voltage (110V/230V) LED bulbs contain some circuit that could behave funny if it receive the supply in bursts. It could even shorten the lifetime as the primary capacitor in there will be under additional stress. But again this depends on the circuit in the bulbs. Cheaper ones might survive that better but probably flicker a lot (the ones with no build-in switching circuit).

As alternative: Have you thought to skip the inverter and use 12V DC LED bulbs? They might behave better if driven from a PWM source. Or better use LED bulbs that don't need to be dimmed down at all. As side effect: This will have a higher efficiency as you don't to the surplus converting to the high voltage and back down (within the LED bulbs).

[dave_j_fan]

i am making a box inverter and user can use any LED bulb . not a emergency light .. wire length they can use higher

that makes it more suitable also 12v DC bulb is vv rare

[dave_j_fan]

I'm not sure if I understand your plan correct: You try to sequentially power one bulb or probably two  at the time, switch to the next and so on. Is my assumption correct?

In that case you'll probably run into problems. As the high voltage (110V/230V) LED bulbs contain some circuit that could behave funny if it receive the supply in bursts. It could even shorten the lifetime as the primary capacitor in there will be under additional stress. But again this depends on the circuit in the bulbs. Cheaper ones might survive that better but probably flicker a lot (the ones with no build-in switching circuit).

As alternative: Have you thought to skip the inverter and use 12V DC LED bulbs? They might behave better if driven from a PWM source. Or better use LED bulbs that don't need to be dimmed down at all. As side effect: This will have a higher efficiency as you don't to the surplus converting to the high voltage and back down (within the LED bulbs).

12v bulbs not a option longer cables will be used to put ,say 2 story building .
I have used  220V LED bulbs for very longtime on  almost square wave inverters bulbs dont care  of that .
Keeping inverter cost low is main needed , efficiency is not that of concern as similar inverter running with loong 12hr backup( not having Triac switcher)

[wraper]

You certainly cannot do this. And if you use normal quality LED bulbs which include driver circuit, you won't even decrease power consumption. They will just charge internal capacitor with much higher current in the moment power is applied. Thus reducing it's lifespan. If you need to decrease power consumption, use lower power LED bulbs.

[orolo]

Big Clive wonderfully explains the problem with triac dimming and LED lights in this video.

[Zero999]

You certainly cannot do this. And if you use normal quality LED bulbs which include driver circuit, you won't even decrease power consumption. They will just charge internal capacitor with much higher current in the moment power is applied. Thus reducing it's lifespan. If you need to decrease power consumption, use lower power LED bulbs.

I agree. Another issue is with using a square or modified sine wave, a capacitive ballast, used in many LEDs, the current will be much higher, than the design value, causing unreliability, possibly smoke and fire.

[jeroen79]

I don't get what this TRIAC switcher is supposed to do.
Is it just a dimmer?

If you're starting with 12V DC then converting to AC seems inefficient to me.
Look for suitable 12V leds instead.

[Zero999]

I'm not sure if I understand your plan correct: You try to sequentially power one bulb or probably two  at the time, switch to the next and so on. Is my assumption correct?

In that case you'll probably run into problems. As the high voltage (110V/230V) LED bulbs contain some circuit that could behave funny if it receive the supply in bursts. It could even shorten the lifetime as the primary capacitor in there will be under additional stress. But again this depends on the circuit in the bulbs. Cheaper ones might survive that better but probably flicker a lot (the ones with no build-in switching circuit).

As alternative: Have you thought to skip the inverter and use 12V DC LED bulbs? They might behave better if driven from a PWM source. Or better use LED bulbs that don't need to be dimmed down at all. As side effect: This will have a higher efficiency as you don't to the surplus converting to the high voltage and back down (within the LED bulbs).

12v bulbs not a option longer cables will be used to put ,say 2 story building .

Why not? At lower voltages, the current required for a certain amount of power, will need to be higher, but it's only 10W, which is under an Amp at 12V, so the cable doesn't need to be very thick. If the maximum voltage drop is 1V, at 1A, then maximum cable resistance is 1Ohm. 1mm² cable has a resistance of 18.1mOhm/meter, so the cable can be as long as 1/0.0181 = 55.25m, or 27.6m as two wires will be used: one for the positive and anoter negative.

https://www.tlc-direct.co.uk/Book/5.3.6.htm

[Twoflower]

OK, Hero999 beat me with the post by a few minutes. But I'll post it anyway 

The statement "about the higher drop because using 12V compared to 230V" doesn't really count for such low loads. Your schematics show a 10W inverter to 4 bulbs. That allows max. 2.5W per bulb. At 12V this is 210mA. Assuming a 50m (actually 2x50 as you have the return wire as well) wire with 1mm^2 has about 1.7Ohm. That means you loss at the wire is less than 74mW.

Of course if you want them to 'glow' dimly you can probably drive the LEDS with even lower power and the cable losses will go down a lot. At 1W the losses are already down to 12mW as the current appears squared (P = I^2 · R).

If all bulbs are 50m away that sums up to 300mW. Please tell me that your self build inverter has lower losses than 300mW or better than 97% efficiency. Which would be extremely well for a 12V to 230V inverter, you could make money with the design.

Edit: Changed calculations from 5 to 4 Bulbs..

[dave_j_fan]

it is not a design challenge ,,,
purpose is to deliver low cost inveter for small shop and students

12v dc wireloss make  unsuitable for little longer lenths of wire where two bulbs will light up ;
like a poor mans house

then u may ask  why not make 80watt inverter ?
this his cost bench mark and needs bulk battery

even if loss is low 12V leds are vry rare to find , and  during gridpower they need 12V SMPS to run adding to inverter  cost 
(inverter auto switch)

[Zero999]

it is not a design challenge ,,,
purpose is to deliver low cost inveter for small shop and students

12v dc wireloss make  unsuitable for little longer lenths of wire where two bulbs will light up ;
like a poor mans house

then u may ask  why not make 80watt inverter ?
this his cost bench mark and needs bulk battery

even if loss is low 12V leds are vry rare to find , and  during gridpower they need 12V SMPS to run adding to inverter  cost 
(inverter auto switch)

What's the maximum wire length?

As we already stated, the loss in an inverter will exceed that of a 27.6m, 1mm² cable, at 12V 1A, which is over 91% effient.

And as 12V LED bulbs are widely available. I suggest MR16 / GU5.3 lamps. I've recently purchased some for my parent's and sister's house. They've very efficient and run cool, compared to the halogen lamps they're designed to replace.

Another option is using a higher DC voltage, such as 24V or more, but I haven't looked into the availability of such LED lamps.

[dave_j_fan]

i request all to see the scenario that all bulbs are not available all parts of world. even 12v ones of substandard quality in many parts 

if the 12v bulb topic is pulled again  i will have to walk off . 


if somone can highlight 230v switching plan that is running on off at very fast rate like 1Khz  please share

running 12v LED , i dont want to do , the reasons already stated ...... please reply on 230v led  only

[Zero999]

Why not buy an off the shelf 230V inverter? It will be much cheaper than making one.
https://m.ebay.in/itm/3-LED-STRIP-SMD-WATERPROOF-LIGHT-MODULE-5050-WARM-WHITE-DC-12V-FOR-CAR-BIKE-/181612437698?hash=Ng==

The LEDs can then be switched using plain old mechanical relays.

EDIT:
Sorry missed this:

if somone can highlight 230v switching plan that is running on off at very fast rate like 1Khz  please share

Why do you want to do that? Do you want to dim the LED? If so, that's not feasible with 230V 50Hz.

Why not use a dimmable LED? If so you'll most likely need a pure sine wave inverter.

Another option is several lower powered LEDs and a circuit to control how many are switched on.

[dave_j_fan]

Hero999,
post 0 has all details . Why all are serving 12VLED     

for the the ones who dont read  post 0

- It is NOT a tip top light
-it is NOT dimmer
-YES its is SOMTHING else

" it is to switch load very fast so that 10W inverter driver 20watts LED "

 i hope no 12v LED suggestions will come

[dave_j_fan]

my inverter is $5 inverter compact , "DIy"
and 10watts capacity

can it drive 4 of the 5watts LED

[Zero999]

Hero999,
post 0 has all details . Why all are serving 12VLED     

I posted the wrong link:
https://m.ebay.in/itm/150-Watt-Inverter-12V-to-220V-DC-to-AC-Converter-Board-For-Home-Car-Solar-DIY-/282609533548?hash=NA==

i hope no 12v LED suggestions will come

Don't be so childish! You don't make the rules here. People are free to suggest what they like. If you don't like it, you're free to ignore it.

for the the ones who dont read  post 0

- It is NOT a tip top light
-it is NOT dimmer
-YES its is SOMTHING else


" it is to switch load very fast so that 10W inverter driver 20watts LED "

Bad idea. It wont work. If you can't get a larger inverter, you need lower power LEDs.

my inverter is $5 inverter compact , "DIy"
and 10watts capacity

can it drive 4 of the 5watts LED

No, that would overload it, causing it to overheat or some protection circuit to kick in.

If you've made the inverter yourself, then why not post the schematic and a picture so we can suggest how to increase the power rating to 20W?

[Twoflower]

As many times said: Will it work? --> Probably not.

And as this was said we tried to provide you alternative solutions which in general, but not for every case, is superior to your solution. And as we don't know your specific problem we just provided a solution that works in general. If you're not happy with this, you should provide more input to work with. Or take the short answer to your question in the subject line: Probably not.

Switching the different lanes at high speed might have a negative impact at a) The losses on the cables and b) emit electro magetic noise.

As this was noted here: Your results might be unpredictable. As there are different ways to implement 230V LED bulbs. From 'put as many LEDs in series plus a small resistor' to a full blown SMPS. If the LED bulbs contain a SMPS which might not behave as you hope. The input capacitor will have a high inrush current which might exceed the rated 5W of a LED lamp in operating mode. If you switch off and on the supply the high inrush current will probably repeat. If you use the 'simple' ones they might start to flicker annoyingly.

And something you should consider while implementing your inverter: Be aware that some LED bulbs might require a frequency close to 50 or 60Hz. If the bulbs use a capacitor to reduce the line voltage that could fry the bulbs easily.

[dave_j_fan]

I thought why not make the jig ...

 The bulb fry myth has been busted , i was able to reach a steady glow
 the SCR based sequencer works beautifully!
 All 4 channels are active ... but SCR and bulb is on one channel
 i will add 3 more SCR and bulbs .

 testing with 4w PHILIPS bulb on 230V AC
 I have been using SMPS LED lamps , they seem to respond well to few Khz frequency
 all shops and places use squarelike inverters with higher switching freq. the bulbs are doing just fine.
 (may reduce 1year life, but thats ok  of the avg life is say 4 year , reducing to 3year is unnoticable)

 However , i have delivered all inverters to poor and needy. I will make one 10watter
and check if its driving well .

But i appreciate the know how shared so far

[dave_j_fan]

Hero999,
 buying 150w inverter not an option ..most of these are china clones cant be sure of reliability .
 the higher watt inverters waste more watts if the load is 10-20w .

when Qn is : can i drive 20w load on 10w with sequencer
Answer cannot be make 20w inverter

i can make even 100watts one ... but cost and needed battery will make it unusable for the masses .

next is regrding posting my inverter scheme.. thats design trademark
its is $5pack with charger and inverter and autoon combo... with battery protection circuits 

[Zero999]

I thought why not make the jig ...

 The bulb fry myth has been busted , i was able to reach a steady glow
 the SCR based sequencer works beautifully!
 All 4 channels are active ... but SCR and bulb is on one channel
 i will add 3 more SCR and bulbs .

 testing with 4w PHILIPS bulb on 230V AC
 I have been using SMPS LED lamps , they seem to respond well to few Khz frequency
 all shops and places use squarelike inverters with higher switching freq. the bulbs are doing just fine.
 (may reduce 1year life, but thats ok  of the avg life is say 4 year , reducing to 3year is unnoticable)

 However , i have delivered all inverters to poor and needy. I will make one 10watter
and check if its driving well .

But i appreciate the know how shared so far

Yes, you need an LED with a switched mode power supply. There will be a limit to the maximum frequency of the supply voltage, because the bridge rectifier on the input stage will gradually become less efficient, as the frequency increases. Running on 200V to 300V DC is another possibility.

Hero999,
 buying 150w inverter not an option ..most of these are china clones cant be sure of reliability .
 the higher watt inverters waste more watts if the load is 10-20w .

when Qn is : can i drive 20w load on 10w with sequencer
Answer cannot be make 20w inverter

i can make even 100watts one ... but cost and needed battery will make it unusable for the masses .

next is regrding posting my inverter scheme.. thats design trademark
its is $5pack with charger and inverter and autoon combo... with battery protection circuits 

If you designed the inverter, then you should know whether it can power a 20W LED or not, so why are you asking that question here? There's no point in keeping the schematic for your inverter secret. There are 100s of schematics for inverters, which can be found on the Internet and many people here are capable of designing one from scratch.

Or is the question not about the inverter, but the sequencer? Can you post a schematic for that or is it a secret too?

[mikerj]

I am at a total loss to understand the point of this.  Rather than trying to dim a 10W lamp so it only consumes 2.5W, why not start with a 2.5W lamp?

How are you intending to switching a TRIAC on/off at a frequency greater than the zero crossings of the 50/60Hz line frequency?

[Zero999]

I am at a total loss to understand the point of this.  Rather than trying to dim a 10W lamp so it only consumes 2.5W, why not start with a 2.5W lamp?

How are you intending to switching a TRIAC on/off at a frequency greater than the zero crossings of the 50/60Hz line frequency?

Perhaps the inverter generates a higher frequency than the normal mains?

[ogden]

I would like to disagree to most of the LED bulb horror stories told here and ask everybody to think how it could work, not how it can fail. - Because after all original poster is doing good job - he is trying to make our world better place.

My two cents: 10W power is so low that I would not bother about sequential switching, any LED switching at all. I would run all the LED bulbs in parallel - to save on wiring in many installations and create 10W PWM-dimmable AC square wave inverter with input current limiter. Current limiter as safeguard against inverter overload and output short. Also it is worth to consider optional frequency control in 50-400Hz(?) range. Maybe it can help with some (too smart or too dumb) LED bulbs or reduce flicker. What's more or less clear here - lot of testing with various LED bulbs needed.