Backyard Aquaponics
A place to discuss aquaponics

Here is a link to a cheap inverter.

150W cont.
300W surge

>90% efficiency

would be handy for those toying with solar setups

http://www.dailydeals.com.au/product_in ... ts_id=9056

http://www.dailydeals.com.au/product_in ... ts_id=1325

It is a pretty good price Steve.... definitely only for small stuff... it doesn't say if is electrically isolated or not which is a worry... For $79.95 @ Jaycar you can get a Powertech 300W (1000W Surge) inverter, on special atm. I bought one to muck around with... However if these modified sine-wave inverters come anywhere near 90% efficiency I would be very surprised...

Why would the Mod. sine wave have lower efficiency? Agreed that some things don't like mod. sinewave, but as far as engergy in energy out why would that lower efficiency.

But i'm playing devils advocate, you'll notice that it says someting like "best case efficiency" LOL

Not a bad toy though for the price, and it will run the pump that is servicing my system ATM.

It will easily run a pump no worries... I just love nitpicking the specs on cheap electronics... second nature... if there is heat there is loss, buzzing/noise - loss, it it needs a fan - loss, more %THD - loss (it is nevertheless a mod. square wave).

yep, i don't bother with the analysing of specs on cheap electronics, if i pay it $39 then i KNOW what i'm getting

mod. sine wave makes it sound so much better than mod. square wave (which is more accutate a description!)

Still, better than the old square wave ones, the caps in the fluro lights didn't like that very much! I thknk you used to have to take them out.

Inverters have higher efficiencies at larger loads (near continuous rating). All inverters have an idle loss. The larger the capacity of the inverter, the larger the idle loss. I am running my whole system from deep cycle golf cart batteries and use several small inverters instead of one big to minimize loss. Also, I use a computer to control loads and I like to keep them seperate to minimize the affects of component failure. I have cheap inverters that run near 90% at loads close to the continuous rating. It is hard to be exact because the waveform affects the efficiency percent. I just look at the amps from the battery and compare to the pump wattage or current info. I got about 86% doing it that way.

cool info

Okay, so that everybody is on the same wavelength with the inverters:

240vac pumps (xxx watt rating) are used to move the water around the system

An inverter uses 12vdc input and converts it to 240vac to run the pumps
The inverter continuous flow rating should be as close as possible to the total pump wattages for best efficiency.

Deep cycle 12v batteries are used to supply the input to the inverter (battery rating 75AH? – more?)

The batteries can be charged by solar panels and/or 240vac battery chargers

12v will operate the power door actuators

So all connected, it includes a power backup

Have I missed anything?

Doug, before you jump on me, I just read your description on the "backup power supplies" and realised I have repeated your post, I would just like to let you know that you got it right on the other thread

just to throw a spanner in the works.......i did some readng on a universal type motor, (had some theory to cover on differnt motor types). it has brushes and will operate on either AC or DC, Just a bit of info for yas.

How can we take advantage of Universal Motors?

Are they just more tolerant of squared off approx of sine wave?

Do they cost more?

I do wonder if the inverter waveform will affect the life of some of my motors.

Hey all of you electronics propellerheads (and I mean that in the nicest possible sense, honestly ). Can you suggest a good source, or book, or even better, a web site for someone like myself who would like to learn more about electronics.

I'm usually able to locate pdf'd books and stuff online too (gotta love those torrent sites), so if you can even suggest a good title to search for that would be helpful. Cheers.

www.epanorama.net is a good site for ideas on ciruits you can build.

sorry, haven't come across many.

I can give you the name of a refernce book i'm using for motors at the moment, it covers electrical theory from ohms law all the way up to starting configurations for three phase motors (and everything inbetween!)