Need help choosing a DC to AC converter for solar project

[edutech4schools]

Hi,

 

I have a solar panel connected to a car battery but need this to give 240v but have found different types of converters to choose from.

 

I would like to be able to power a small radio, recharge my phone / laptop (not all at the same time)

 

Some converters or is it inverters? have sine wave and some have modified sine wave. I assume some kind of sine wave is best rather than square wave but not sure which.

 

What watts would I need? Thinking about 300w

 

Does this look good? http://www.amazon.co.uk/PURE-SINE-WAVE-POWER-INVERTOR/dp/B005ERFDGU/ref=sr_1_1?ie=UTF8&qid=1350228772&sr=8-1

 

Thanks for any help.

[unixman_again]

In general sine wave is much better for your equipment than square wave. I'd recommend that you talk to the people at Maplins or similar electronics store; they should know about inverters. Here is a good looking one: 600W 12V Inverter

[Dos_Box]

Moving to Hardware forum.

[edutech4schools]

Is a sine wave and a modified sine wave the same thing?

 

I find Maplins useless in my area for tech info.

[Oaktech]

a sine wave is actual gently undualting wave, which is actually quite difficult to 'make'. A modified sine wave is an approximation of a sine wave made up of increasing/decreasing amplitude square waves, which is much easier (cheaper) to make, but if your gear is in any way sensitive it will, over time, bork it. True sine wave is the way forward.

[unixman_again]

Modified sine waves and sine waves are different. Have a look here Power inverter for a good explaination. If the staff at your local Maplins are useless (like you I've found most are) talk to their phone line. I always do it I want info on something. Having done that, I go to the shop and get it.

[pcstru]

What watts would I need? Thinking about 300w

 

300w would be find for a radio or device charger. It will probably be a bit of a waste as both will run off wall-wart type convertors no doubt producing a DC voltage somewhere between 5-12 volts and neither will be particularly power hungry. So you will be going from 12v DC -> 240v AC back to 3-12 v DC. If you know the inputs of the devices, you could build a 780 based regulator for about 50p.

 

ETA - I wouldn't worry too much about modified sine wave. Most consumer devices use AC->DC supplies which are perfectly capable of dealing with a mucky supply.

Edited October 15, 2012 by pcstru

[edutech4schools]

wart type convertors

What is this? I have done a google but the wart converters seem to require an AC input. Am I looking at the correct devices?

 

My solar panel comes with a female cig lighter. Not wanting to blow up by expensive Samy phone would I be ok to connect straight to the female cig lighter? presumably this is no different to charging in a car or should I go through a 240v converter and use the normal 3 pin plug?

[pcstru]

What is this? I have done a google but the wart converters seem to require an AC input. Am I looking at the correct devices?

Yes. Walwarts usually go from 240v AC to some small DC voltage.

My solar panel comes with a female cig lighter. Not wanting to blow up by expensive Samy phone would I be ok to connect straight to the female cig lighter? presumably this is no different to charging in a car or should I go through a 240v converter and use the normal 3 pin plug?

 

If your phone comes with a car cigarette plug charger, then you will be OK to plug that into the solar panel.