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ovuriri
Apprentece
10 Posts |
 Posted - Feb 15 2007 : 12:37:56 PM
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| hello audioguru,i appreciate what u're saying,it making me understand why my circuit burns out.but audioguru,i prefer using mosfets transistors,i like to have the circuit using mosfets transistors.i love u,kenny. |
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ovuriri
Apprentece
10 Posts |
Posted - Feb 16 2007 : 08:22:13 AM
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| hello audioguru,i also need to know why u cant simply use that circuit diaram,becos i found a mosfet that has same properties with the bjt transistor.ken |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Feb 16 2007 : 09:41:25 AM
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A 2N3055 power transistor conducts 8A when its base-emitter voltage is typically 1.4V.
A power Mosfet is turned on when its gate-source voltage is 10V. A few "logic level" power Mosfets turn on when their gate-source voltage is 4V.
Mosfets switch much faster than transistors. Therefore a special circuit must be made so that one turns off first before the other one turns on. Or else both are turned on at the same time creating a dead short across the battery with hundreds of Amps of current.
Gary has many projects and one is a Mosfet square-wave inverter with a max power of 500w.
http://www3.telus.net/chemelec/Projects/Inverter/Mosfet-Inverter.htm |
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ovuriri
Apprentece
10 Posts |
Posted - Feb 17 2007 : 10:22:37 AM
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| hello \,audioguru,are u very sure if that circuit works very well.i am using it for a project work and dont have enough money to play with.but do u still think the bjt transistors can work perfectly well without any problems.love u,ken. |
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tim
Mad Scientist
198 Posts |
Posted - Feb 17 2007 : 11:17:20 AM
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| hi all, a resistor is 04.7ohm would 4.7 k ohm would this be the same. |
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Binary 1011001101
Nobel Prize Winner
United Kingdom
569 Posts |
Posted - Feb 17 2007 : 11:41:52 AM
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No, 4.7k ohm is 47000 ohms
0.47 ohm is less than 1 ohm |
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tim
Mad Scientist
198 Posts |
Posted - Feb 17 2007 : 12:41:44 PM
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| can putting multiple resistors in paralelle to achive a value be done? |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Feb 17 2007 : 12:43:15 PM
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| The 500W inverter circuit that I posted has a square-wave output. Lots of things don't operate properly with a square-wave. The inverter is used in The Philippines to power fluorescent tube lights and multi-voltage TVs. it could also power heating appliances. |
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cyclopsitis
Nobel Prize Winner
Canada
732 Posts |
Posted - Feb 26 2007 : 08:27:58 AM
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Tim, Yes you can put resistors in parallel to achive an uncomon value. The formula for parallel R is:
Rt = R1 X R2 / R1 + R2 = Rt
K |
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tim
Mad Scientist
198 Posts |
Posted - Feb 27 2007 : 07:44:02 AM
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| does the same apply to putting resistors in series as well to get a value? |
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cyclopsitis
Nobel Prize Winner
Canada
732 Posts |
Posted - Feb 27 2007 : 10:19:04 AM
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No, Resistors in series add their value for ex. one 10 ohm resistor in series with a 20 Ohm will equal 30ohms in the circuit. The same with inductors (coils). The Henry value adds together in series. Capacitors are the opposite. Caps in parallel add together the (uf rating) and in series they divide. You can probably find a write up on Google about it if you want to actually read it for yourself. I like studying this stuff I like knowing how things work so happy searching!
Ken |
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omleje
New Member
Nigeria
1 Posts |
Posted - Mar 02 2007 : 08:52:13 AM
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| how long do the inverter works and can the circiut be made to produce 220v,5000w,50-60Hz? |
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Aaron Cake
Administrator
Canada
6717 Posts |
Posted - Mar 02 2007 : 09:23:05 AM
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quote:
Originally posted by omleje
how long do the inverter works and can the circiut be made to produce 220v,5000w,50-60Hz?
Please at least take a quick look over the topic before you post a question. This circuit does not work very well in most cases, and building an inverter of that size is completely impractical. |
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CATWHISKER
New Member
1 Posts |
Posted - Mar 07 2007 : 12:12:24 AM
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quote:
Originally posted by omleje
how long do the inverter works and can the circiut be made to produce 220v,5000w,50-60Hz?
JUST TAKE THIS AS A SUGGESTION.IF U HAVE TO BUILD AN INVETER, FIRST,BE SURE THAT IT IS PRACTICAL IN THE VERY SENSE!SECONDLY,CHOOSE A CIRUIT[DESIGN]THAT IS SURE TO BE 100% EFFICIENT.
THANKS, GOOD LUCK! |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Mar 07 2007 : 09:02:59 AM
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It is impossible to make an inverter circuit that is 100% efficient. The transistors in an inverter pass many Amps of battery current and therefore get hot. The heat is wasted and reduces the efficiency.
If an inverter uses very good Mosfet transistors to switch the current then it would be about 90% efficient.
If it uses power transistors in a good design then it is about 80% efficient.
The inverter circuit on this site is about 40% efficient. |
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Topic |
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12/120V inverter again
