- is this a sine wave inverter or square wave inverter?
Ans.
If you look at the schematic there is no part that produce square wave, this is mdified sine wave 100%, the C2, C3, C4, C5 generate charge and discharge that becomes sine wave. Output to Q5 and Q6 from voltage divider of R11-R12, and R8-R9
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Feb 4, 2010. 8:31 AMbr>
In my setup, using a Harbor Freight inverter, the battery voltage drops below 12V at 30 amps output. It automatically shuts off below 11 V. Do you just allow the AC voltage to drop on your system? What AC voltage do you get after draining one battery 30 amps for an hour?
I find with even 2 batteries in parallel, I can't keep going for more than 15 minutes at 20 amps.
Ans.
if you use other inverters, i guess that the inverter you are using is switching power supply in stead of coil transformer. Your inverter auto shut down after read 11 V, this is your inverter system voltage control. Our Inverter does not effect voltage drop, it still running until you turn OFF manually. For an hour voltage (output) does not drop. I guess you check your battery during the charging if the amp meter (cramp amp meter) read higher amp after fully charged this means your batt run out of life time ampcapacity. You should change newer batteries.
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Feb 9, 2010. 3:29 PM
i forgot to mention that a 12v or 24v input is prefered and a 120 or 115 output is required
i was wondering how much would it cost for you to build me a 5000 watt and/or a 6000 watt
thank you
Ans.
Hi ,
input 12 v dc, output 5000 watts and 6000 watt AC output, 110volt or 115 volt
5000 watts the require power transformer is 430 Amp,
Inverter to be applied should be 10320 watts
Price of inverter: xxxx USD
Price of transformer: xxxx USD
6000 watts the require power transformer is 521 Amp
Inverter to be applied should be 12504 watts
Price of inverter: xxxx USD
Price of transformer: xx,xxx USD
Time of production : about 30 days.
Price not yet include shipping cost, the goods will be shipped by Sea Freight. Let me know your discharge port and address to quote shipping.
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Feb 4, 2010. 4:40 PM aci925(author) says:
In addition, do not measure your battery from reading voltage, voltage drop but the ampacity still available if you continue re-charging the battery, it will damage the lead cells of the battery. On the other hand measuring voltage during charging is also prohibited, your batt voltage can achieve 12 or 13 volt in a short time, this will mislead you think it is fully charged. But in a real physic your battery is only reach the voltage level but not the ampacity.
Buy battery charger that have amp meter reading build in.
REMEMBER **** DO NOT measure the battery from voltage.
In case the battery is spoil it will cause; 1) Less ampcapacity 2) less voltage than usual. Use your volt meter to measure the battery if it reads below 13 volt this means your battery lead cells is running out (spoil) low quality. Check the distrill water in the battery also. So how to repair battery ? Remove the cap and drain out the water, and put the distril water and shaking the battery and pour out again (to get rid of sodium particle which effect the electron flow internal battery cells). Then put the battery water (i don't know what is called in english) at the standard level. Leave the cap open and wait about 10 minutes then start re-charging. With this method you can use battery for another 1 more years before re-new.
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Feb 6, 2010. 9:23 AM
Hi......Thank for posting very rare and useful information about POWER
INVERTERS.....I have a Motor Driven MPA ( Permanent Magnet Alternator )
which can produce 120 AMPS on 12 V at 2400 RPM....can you please advice
me,which INVERTER shall i use to meet 8000 Watts in 12 hours...
i am ready to buy one if freight and other charges with in my butget...
please contact me on email address.
thank again ...
with best rgds and wishes for your success,
Ans.
Hi ,
You want 8000 watts application, you did not tell me the voltage you want. Let's say you want 220 volt AC, 8000 watts which is 36.36 Amp. This is about 37 Amp on secondary side. You need to apply 363 or 370 Amp power transformer on primary side. The needed inverter is 24 volt x 370 Amp = 8880 watts. (because 12-0-12 = 24 volt). One piece of battery 370 A can operate 1 hour. You want to run 12 hours so you need to have 12 pcs of battery. In the market if you can not find 370 A batt, you may apply 400 A battery. The total amp is 370 A x 12 = 4440 Amp, then you only need 4440 divided by 400 = 11.1 or 12 pcs battery.
Now you have mentioned your alternator can generate 120 A, 12 VAC output. You need to convert AC to DC in order to charge the battery. The require electric current to charge 1 battery is about 20% of the battery ampacity. Thus 400 A battery you need 80 A charging but I recommend 70A.
But you have 120 A alternator which is not enough to charge all 12 pcs at one time for 70 A setting, i suggest you charge 10 A for each battery. So you can charge 12 pcs of battery at one time. Each battery require 40 hours (400/10=40 hrs) for one time 12 pcs battery parallel connection. You may increase the RPM speed from 2400 to 2700 RPM to maximize the amp when charging all batteries. In case you can not increase the RPM, then i suggest you charge 10 pcs of battery at a time.
Those who's playing with inverter, you need to know not only inverter but you need to know (1) Ampacity of the battery (2) Amp application on transformer output side (3) Amp application on inverter side (4) Total amp you want (4) Charging battery knowledge.
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Feb 5, 2010. 10:21 PM
There must be a way to reduce the huge and expensive block of metal of the transformer? (Just like a relatively light power brick did replace big and clunky transformers)
Ans.
Toroid transformer is an option to reduce the size of transformer, but it is hard to find the maker. Another option is to generate direct AC 220 volt in stead of 12-0-12 Volt. But could not find the high power transistor to do that.
If anyone knows what transistor please advise.
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Feb 4, 2010. 9:18 AM
Very nice! I just had some questions about the transformer. You said you designed it, could you provide any more details about this process or maybe some good sources of appropriate high amperage transformers?
Ans.
The transformer specification is
Primary input coil is 12-0-12 volt (zero is tab center). Half of 12 is half sine wave cycle and other half 12 is half sine wave cycle. This will complete sine wave cycle for 12-0-12.
Output secondary coil is 110, 220 volt
Rated current is 30 amp, IE type. The weight of transformer is about 90 kg.
You should order as custom made to the supplier.
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Feb 4, 2010. 2:59 PM
that is a huge transformer!
nice instructable.
- Feb 3, 2010. 9:36 PM :
Sweet. This is exactly what I was looking for. My friend has 6 washing machine motors that we're going to try to turn into an electric go-kart.
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Feb 4, 2010. 2:10 AM :
Most washing machine motors are of the synchronous induction type. Which means they run at or a sub multiple of the AC frequency applied to them. This depends on the number of poles within them motor. This isn't important. With this circuit, modify the "sine wave generator" so that you can control the frequency (say from 1 to 100Hz) which will form your speed control. The rest of the circuit is unchanged. Connect it all up and away you go. Fun, lots of fun, but keep all the power circuits well insulated because the voltage generated is lethal. Please post your results so that we can all enjoy the results of your work.
- Feb 4, 2010. 6:00 AM :
wow! thanks for the reply. Your information is going to be really useful when we're making this.
Ans.
Thank you for your comment.
Here is the test results from this inverter.
TESTING RESULTS:
Applied with 12 VDC, 38 Amp lead acid car battery
Washing machine 230 watts 3.70 hours
Desktop PC computer with CRT monitor 15" 3 hours
Lamp 60 watts 15 hours
Color TV 29" 155 watts 5.5 hours
Air conditioner See *Remark below
Microwave 1200 watts 1.42 hours
Refrigerator 6.9 Cubic Foot 7.78 hours
Fan 38 watts, 0.18 A 21 hours
etc as desired
*Remark
Air conditioner 8000 BTU start up motor require about 4 amp, normal running require about 2.5-3 amp. This inverter can run aircon about 1 hour for 1 piece of car battery. Battery parallel connection will increase longer operation.
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