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audioguru
Nobel Prize Winner
Canada
4146 Posts |
 Posted - Jun 02 2005 : 09:37:18 AM
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quote:
3) Added diodes (for the two sides only), between the cap and the 180 ohms resistor that goes to the base of the transistor.
The transistors on each side should be in parallel with their bases connected together, then there is only two sides.
The caps won't charge and discharge properly with diodes between the cap and the resistor. The diodes should be in series with the bases of the transistors to protect them from avalanche breakdown. Then the bases need an additinal 1k resistor to ground to turn them off.
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John Doe
Apprentece
Mexico
14 Posts |
Posted - Jun 04 2005 : 11:13:28 PM
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I will make modifications you tell me, it was wrong connected; but if it still doesnt work, I am leaving this project and will try the 200 watts inverter in the web I told you. Or I will seek another. I will keep you in touch for knowing if this one worked or not.
Thanks
Francisco Javier Olvera Moreno
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engineer66
New Member
Jordan
1 Posts |
Posted - Jul 23 2005 : 06:17:37 AM
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quote:
Aaron or YS -- could you please tell me what the next higher power transistor than that of the 2N3055 is? Amperage and voltage. This is to use in this crazy 12V-120V inverter. Thank you...Tim.
fadi |
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audioguru
Nobel Prize Winner
Canada
4146 Posts |
Posted - Jul 23 2005 : 07:34:12 AM
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Tim,
Higher power transistors won't make much difference in this simple circuit.
First, the circuit needs to be fixed so that its capacitors are not backwards and so that the base-emitter of the transistors don't breakdown. Then the 2N3055 transistors will conduct about 6.3A and the project will make about 63W at 118V, when the battery is 13.8V.
Second, the base current for the transistors needs to be increased so that paralleld output transistors can provide more power.
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jecjec
New Member
3 Posts |
Posted - Aug 03 2005 : 6:27:11 PM
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Hi Audioguru,
May i seek ur advise regarding my newly purchased 500watts power inveter. My question is , can i use my 3/4 Hp. electric motor on it and what size of battery would u recomend for me to use.My second question is, will it be possible to connect my inverter into my old model jeep that has original alternator ? some auto-technician said that my original alternator is only 25ampere and it impossible for my inverter to produce the amount current to run my electric motor.Im seeking second opinion,pls.need ur advise,many thanks in advance.
Jessie
p.s. my inverter is modifide syne
wave
Edited by - jecjec on Aug 03 2005 6:33:26 PM |
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audioguru
Nobel Prize Winner
Canada
4146 Posts |
Posted - Aug 03 2005 : 11:28:52 PM
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Hi Jecjec,
The electrical power used by your motor depends entirely on how much mechanical work it is doing. I have my 1/2hp furnace fan running at its limit of 10A, therfore if your 3/4hp motor is fully loaded then it would use 1800W and your inverter is much too small. A 3/4hp motor might draw 18,000W when it starts. If your 500W inverter is trying to power it then you can kiss the inverter good-bye.
Many inverters operate at their max rated power for only a short time. If yours is rated to supply 500W continuously at 120V, then it will draw 43.5A from a 13.8V car battery. The Jeep's little alternator will probably overheat trying to power it and also charge the battery. Get a more powerful alternator.
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audioguru
Nobel Prize Winner
Canada
4146 Posts |
Posted - Aug 03 2005 : 11:31:53 PM
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Hi Jecjec,
The electrical power used by your motor depends entirely on how much mechanical work it is doing. I have my 1/2hp furnace fan running at its limit of 10A, therfore if your 3/4hp motor is fully loaded then it would use 1800W and your inverter is much too small. A 3/4hp motor might draw 18,000W when it starts. If your 500W inverter is trying to power it then you can kiss the inverter good-bye.
Many inverters operate at their max rated power for only a short time. If yours is rated to supply 500W continuously at 120V, then it will draw 43.5A from a 13.8V car battery. The Jeep's little alternator will probably overheat trying to power it and also charge the battery. Get a more powerful alternator.
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jecjec
New Member
3 Posts |
Posted - Aug 04 2005 : 02:33:55 AM
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Hi audioguru,
Thanks for ur precaution otherwise my inverter will be history.what about 1/4 Hp at 200 watts and i will be using variac at 500watts to start the motor.I tried it for a while luckily my inverter survive but my car battery drain so quikly,what size of battery suit my inverter that would run at least for a while to process my crops.
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moody
Mad Scientist
USA
326 Posts |
Posted - Aug 06 2005 : 8:13:52 PM
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ive seen this post grow over time but never had to read this because ive never had to read the 12 to 120V 1,000 Watt converter...untill now
im trying to run a saw or something from the power of my car...this saw must be able to cut metal from the scrap yards.
i was thinking the following tools to run
bandsaw (portable)
sawzall
my question is...
is this 12 -120v inverter worth making?
i was looking at this inverter which will get to about $100.
http://cgi.ebay.com/Vector-1000-Watt-Power-Inverter-VEC049C_W0QQitemZ5795949758QQcategoryZ85805QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
If i buy all the parts for this inverter project will i end up spending $100
if thats true than ill just buy the ebay one
"I reject your reality and substitute my own" -Adam Savage (Myth busters) |
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audioguru
Nobel Prize Winner
Canada
4146 Posts |
Posted - Aug 06 2005 : 11:49:44 PM
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This project's inverter doesn't work. Buy that good one.
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moody
Mad Scientist
USA
326 Posts |
Posted - Aug 07 2005 : 12:46:20 AM
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sure will
thanks
"I reject your reality and substitute my own" -Adam Savage (Myth busters) |
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plutonium233
Apprentece
16 Posts |
Posted - Oct 10 2005 : 7:20:25 PM
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Hello World,
I have followed this thread for a while, and I just want to offer some suggestions. Firstly, listen to what audioguru says. From the viewpoint of a double E, I agree with his analysis of the circuit. His modifications should have fixed many of the problems with the circuit; however, the circuit has inherent inefficiencies. For you all who need a powerful inverter, they sell 5kW models for a decent price (around 500 american dollars) and most of them are more than 90% efficient which is more than I can say for some of the circuits I've seen here. I use two, more expensive syncable units with some extra bells and whistles in a ups configuration for a backup on most of the circuits (such as my home automation system/av/security, lights, and most everything else) in my home until my 20kW Cummins can start up. As for batteries, all you really need to do is parallel a bank of deep cycle batts. Some prefer to use two 6v batteries in series instead of 12v batteries when doing this because of the increased power density. I used 12v for mine because I had a great source of them. It also seems that many of the people in here need a good solid course on thermodynamics !!! As audioguru mentioned before, you can't get something from nothing, and you can't keep converting from one type of energy to another. It gets more and more inefficient, especially with poorly designed circuits. Study this deltaE = q + w. It is a basic idea of whats going on. If you put 100 watts into a closed system and get only 80 watts back out as useable work energy, then guess what. 20 watts turned into heat energy. I guess some could argue that they use the heat to heat their home... no need to run a heater on the inverter I guess.. HaHa.
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audioguru
Nobel Prize Winner
Canada
4146 Posts |
Posted - Oct 10 2005 : 8:31:36 PM
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Hi Plutonium.
Ha, ha. and thanks.
On another forum many frustrated people argued about this "inverter" project and asked to have it deleted. They also discovered that a 500W inverter project also didn't work and I helped them fix it.
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electroman2000
Apprentece
Malta
5 Posts |
Posted - Oct 14 2005 : 09:11:17 AM
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hi to all,well i am new here but i have already build the 500W inverter and has been using it to power my garage for about a year now! it works perfect and when i tested i found that it could reach almost 700w if the transformer has a relative large secondary and the transistors used are 2n6050.the best is to use 2n5886 rated 25a which are more than enough for battery power.well i have pictures for you to see how i build it and how i seperated the two heat sinks using them as sides of the case! this is my website adress of my built inverter with pics of construction: http://inverter500.blogspot.com/ leave comments if you need help in construction i am pleased to be of help.
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electroman2000
Apprentece
Malta
5 Posts |
Posted - Oct 18 2005 : 05:34:15 AM
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quote:
hi to all,well i am new here but i have already build the 500W inverter and has been using it to power my garage for about a year now! it works perfect and when i tested i found that it could reach almost 700w if the transformer has a relative large secondary and the transistors used are 2n6050.the best is to use 2n5886 rated 25a which are more than enough for battery power.well i have pictures for you to see how i build it and how i seperated the two heat sinks using them as sides of the case! this is my website adress of my built inverter with pics of construction: http://inverter500.blogspot.com/ leave comments if you need help in construction i am pleased to be of help.
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12/120V inverter again
