Author Options:

A 12VCD to 220VAC inverter that needs to power a TV(110-240 volts,50-60 hertz,75 watts) for not more than 10 seconds.? Answered

OK,so we've got this new LED flatscreen.There are frequent power disruptions,power failures,load shedding etc where I stay and most people have an inverter installed in their homes to run their devices during power cuts.We have an inverter in our home too but here's the problem-When the power from the mains is cut and the inverter starts to do its role,there's a small delay between this process which is hardly noticable but long enough to shut my TV off.Say if we are watching a program and suddenly there is a power failure,all the devices continue to work normally on the inverter except the T.v which has to be turned 'ON' again by using the power key in the tv remoye or on its panel.I guess it isn't good for a Tv to just shut off like that without first turning it 'OFF' with its remote.I thought if I could build an inverter that can run on a rechargeable 12 volts battery and power the T.V for a few seconds,filling in that delay I mentioned above.This way I could prevent my T.V from turning 'OFF' like that and could ensure it a greater life.I intent to add this new inverter as a backup power source until power from the main inverter begins to get utilised.I've included a schematic to give you a better understanding of what I intent to make.Thanks in advance for the time you spent on helping me out.


buy a UPS they are available for computers Uninterrupted Power Supply

Amazon example

Amazon.com will have the same

Thanks to everyone for your valuable suggestions.I've been over the idea of getting an UPS/Inverter to do the job but then I thought,I already have an inverter at home and didn't want to spend money on another one since I've already described that its necessity is just for a mere 5 seconds and I didn't think the cost was worth it.But still considering your suggestions I enquired with the shop from where I bought my LED flatscreen and they are of the opinion to use a stabilizer which also solves my problem by acting as a temporary power source(I think its because of the huge capacitors in it).A guy from the store visited me and analysed the situation.He also tested this stabilizer on my T.V and it did cover up my worries.Since the stabilizer provides dual advantage than an inverter,I quickly placed an order for such a stabilizer and 'll reach me tomorrow.Once again sincere thanks to your interest for helping me out.

+ 1 for Rick. A UPS will certainly work as Rick suggests, however, a lot of good inverters these day have circuitry that can handle the switching and load that you require (or have a UPS option to handle larger loads like workstations with CRTs etc). I have been running my house off an inverter for 10 years. I have a 120W LCD TV and it certainly chugs along happily when the power goes out. I have a simple 800W Falcon SuKam running our entire house (minus fridge and water heater - we have them running in our office and shelters too), they are popular around India. I like this model as it really can take a lot of abuse - if you try to run your water heater off it, it will simply whine and not blow up. It charges intelligently when there is power so you can't overcharge. As you would expect will auto switch so if you wire it for lights etc then when there is power it just uses that, when power goes out it "instantly" switches over to using the battery. For such an inverter you are looking at US$100-150. I would try to source some thing with the same sort of specifications.

The other thing is that your TV might be super sensitive to power fluctuations, but I would still try something like my inverter as it certainly does the trick for our similar devices (it also switches automatically between low power and high power modes to be more efficient).

+1 for Rick's idea about a UPS.

What you have designed is more or less what you already have - an inverter that gets going when the mains is down. The magnetic fields in the transformer and relay coil need time to break down, your new inverter  needs time to power up, stabilize its output to the 200VAC and so on.

I don't think, you have to worry about power cycling your TV - if it is a modern LCD. Old CRTs may be a different story.

Check the menus of your TV maybe it has a kind of kiosk mode that powers it on when the mains returns.

Rick's right, this is a job for a UPS.