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Binary 1011001101
Nobel Prize Winner
United Kingdom
569 Posts |
 Posted - Apr 14 2007 : 11:17:20 AM
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I saved it as a JPG because express sch saves it as that and no other options, most of the time it is ok.
You can upload to here? I didn't know that, how do I do it
The flip flop I used was a SN74LS76AN. I also tried a darlington pair to drive the 3055, the low power BFY51 transistor hot VERY hot
Anyway, If I use your circuit without the op-amps and in place of the CD4047 there is a 555 and flip-flop giving the correct frequany would it work?
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fedfray
New Member
Indonesia
1 Posts |
Posted - Apr 23 2007 : 12:53:30 PM
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| hi audioguru.... u r an expert for electronic for me...can i ask something? for 500w inverter...can i paralel 6 trafo 10 A at 12 Vac for replacing 60 Ampere trafo 12/220 vac. i think it's more cheaper |
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audioguru
Nobel Prize Winner
Canada
4147 Posts |
Posted - Apr 23 2007 : 4:01:16 PM
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Hi Binary,
The flip-flop is TTL which needs a regulated 5V supply.Its output doesn't go to a high enough voltage for this circuit.
Hi Fedfray,
I don't think you sould connect transformers in parallel. They might not be exactly the same which would cause a high current to flow between them. |
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Binary 1011001101
Nobel Prize Winner
United Kingdom
569 Posts |
Posted - Apr 23 2007 : 4:42:41 PM
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| Ok so would it work if I pass it through a high gain transistor to power to 3055s? |
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audioguru
Nobel Prize Winner
Canada
4147 Posts |
Posted - Apr 23 2007 : 7:36:05 PM
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Hi Binary,
Two 2N3055 transistors in an inverter would allow an output power of only about 80W.
The 2N3055 has a max 3V saturation voltage loss spec at 10A when its base current is 3.3A. The max base-emitter voltage is 1.5V at 4A and might be 2.5V at 8A. A TIP41 transistor to drive each 2N3055 has a max base-emitter voltage of about 1.5V at 3.3A and its base current would need to be at least 220mA. A 3rd driver transistor is needed to supply the 220mA and its base-emitter voltage is about 1V so the total voltage needed to drive the transistors is 2.5V + 1.5V + 1V= 5V. The max output voltage from a TTL flip-flop is only about 3.5V. |
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Binary 1011001101
Nobel Prize Winner
United Kingdom
569 Posts |
Posted - Apr 24 2007 : 02:28:42 AM
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Stupidly ive allready started making it wihtout knowing it will work.
So what if I put a opto-couple on it, not to isolate but to amplify the signal, a LED only needs about 3.5V and the other half I could make into a darlingtion pair...
Just more ideas, |
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audioguru
Nobel Prize Winner
Canada
4147 Posts |
Posted - Apr 24 2007 : 08:04:22 AM
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quote:
Originally posted by Binary 1011001101
So what if I put a opto-couple on it, not to isolate but to amplify the signal
No. Look at its datasheet. Many optical isolators don't amplify. 10mA in produces only 2mA out.
quote:
a LED only needs about 3.5V
No. Look at its datasheet. A white or blue LED is about 3.5V. The IR LED in an optical isolator is about only 1.2V.
In the 500W inverter that I fixed there are four 2N3055 transistors in parallel at the output on each side. They are driven by another 2N3055, which is driven by a medium power transistor, which is driven by an opamp, which is driven from a cmos oscillator operating with a 12V supply. |
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snappyt
New Member
2 Posts |
Posted - Apr 25 2007 : 03:15:45 AM
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| Anyone help with this design for a load of 480 watts @ 240vac...what is the current draw on a 12 volt battery. Thanks. |
XSRE |
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Aaron Cake
Administrator
Canada
6532 Posts |
Posted - Apr 25 2007 : 09:20:01 AM
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quote:
Originally posted by snappyt
Anyone help with this design for a load of 480 watts @ 240vac...what is the current draw on a 12 volt battery. Thanks.
You will find several designs for suitable circuits in this thread already. Just read through it.
To make 480W @ 240VAC out of 12V, you need a minimum of 40A. But the inverter will not be 100% efficient so figure 20-50% on top of that. |
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Sobat
Apprentece
Indonesia
5 Posts |
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cyclopsitis
Nobel Prize Winner
Canada
732 Posts |
Posted - Apr 26 2007 : 01:56:12 AM
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We can't see your link because we don't have a username and PW. If you read through some of this topic you'll find all the info you need for your prject.
Master cyclops haha |
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audioguru
Nobel Prize Winner
Canada
4147 Posts |
Posted - Apr 26 2007 : 11:56:46 AM
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3000W is way too much for an inverter. If you use only 12V then its battery current will be 300A!
You would need to have a large room full of batteries to power it for a short time. Then it will take 1 week the charge the batteries.
Its wiring must be huge and it would need 48 output transistors and many driver transistors.
Its transformer would cost a fortune. |
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snappyt
New Member
2 Posts |
Posted - Apr 28 2007 : 5:58:40 PM
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| Thanks for the help....Aaron Cake |
XSRE |
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Sobat
Apprentece
Indonesia
5 Posts |
Posted - May 02 2007 : 08:40:11 AM
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Hello Master AudioGuru
It's me again, this time i want to build inverter 12 volt to 120 volt, but i can't find HEP 154 silicon dioda in my country, can i change with another diode, what tipe diode can i use for this circuit.
http://www.aaroncake.net/circuits/inverter.asp
Thank you Very much |
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audioguru
Nobel Prize Winner
Canada
4147 Posts |
Posted - May 02 2007 : 09:32:00 AM
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This inverter circuit is too simple to work properly. Its output might be only 25W. Its capacitors are backwards which causes them to explode. Its transistors don't have nearly enough base current and are constantly having reverse breakdown.
Read about it in this long thread. |
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12/120V inverter again
