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cyclopsitis
Nobel Prize Winner
Canada
732 Posts |
 Posted - Dec 13 2006 : 4:44:34 PM
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Thanks Tim i did'nt think of looking at ebay! many thanks!!
Ken |
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tim
Mad Scientist
198 Posts |
Posted - Dec 13 2006 : 4:49:49 PM
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| i have 2 inverters and one is strange it say 200 watts but i kind of got like 300 watts out of it its new in the box and its from a few years ago but it has a huge transformer that looks like it can be modified to put out alot more then 300 watts . i may put it on ebay though cause i dont have the time to play with it. |
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tim
Mad Scientist
198 Posts |
Posted - Dec 13 2006 : 4:52:21 PM
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| and the other one is an old radio shack from the 1980s i had put more powerfull transistors in it and its rated for only 100 watts but now i get about 200 watts. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Dec 13 2006 : 6:22:20 PM
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Most inexpensive inverters have a square-wave output that works fine for heates and incandescent lights. Many electronic products and electric tools with motor speed controls won't work. The circuit is simple.
Then there is "modified sine-wave" inverters that produce a square-wave with a step in it. More things work with it. The circuit is complicated.
The best is a pure sine-wave output inverter that use PWM or class-D to stay cool because their transistors switch fully on and fully off at a very high frequency and their average output is controlled by the duty-cycle of the output pulses. The circuit is extremely complicated.
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tim
Mad Scientist
198 Posts |
Posted - Dec 13 2006 : 7:06:30 PM
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| yea well the one im fixing is enough for me to handle as far as complicated. |
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petermotosh
New Member
Nigeria
1 Posts |
Posted - Dec 14 2006 : 06:59:38 AM
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quote:
Originally posted by Techoduro
No big deal, Aaronīs design ???, a simple oscilator seems to me more like a challenge to make it work as inverter than a serious project, since elementary in circuits told us you could not use it that way but as a driver to other circuit to reach the goal. I donīt think you would use a fork to have soup, all you have to do is using a spoon.
By the way thanks for all the information provided by some of you, which is being very usefull to me.
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Petrotech |
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SAE140
Apprentece
United Kingdom
6 Posts |
Posted - Dec 15 2006 : 11:03:43 AM
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quote:
Originally posted by cyclopsitis
Hi Tim,
Where did you get that power inverter from? Do you have any ideas on what the schematic would look like or have any idea where i would get one from. I was thinking of just buying one and taking it apart.. but hey if you have ideas that would be great.
If you are looking for BIG inverters, then checkout:
http://www.qsl.net/dg5sga/inverter.htm
http://technology.niagarac.on.ca/staff/mcsele/i2k.htm
Both of those guys know how to drive Power Mosfets.
This guy doesn't:
http://www.cadvision.com/blanchas/hexfet/h-bridge2.gif
Getting Mosfets quickly through their linear region when switching large currents is critical to avoid excessive heating - so use a dedicated chip, or at least a totem-pole push-pull driver.
Colin
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Dec 15 2006 : 12:19:24 PM
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Hi Colin,
How about a lousy inverter circuit that has its capacitors backwards and its transistors operating with hardly any base current and having avalanche breakdown like this one? |
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tim
Mad Scientist
198 Posts |
Posted - Dec 15 2006 : 12:41:12 PM
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| hey ken which inverter are you talking about. was it the one i said had a big transformer? where you can get one , well i think this is the only one, and its new i think new old stock. |
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tim
Mad Scientist
198 Posts |
Posted - Dec 15 2006 : 1:34:26 PM
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| i hope someone out there can help me , i have a TO92 transistor number -KSP44013 that im trying to get the data for and cant find it anywhere.maybe someone knows where to look for it , thanks. |
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tim
Mad Scientist
198 Posts |
Posted - Dec 15 2006 : 1:38:50 PM
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| in a pwm circuit they use a pnp and npn,the pnp is a 2n5401 so would the voltage be the same as the pnp for the npn . i think this ksp44013 is npn. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Dec 15 2006 : 1:56:21 PM
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It is easy to measure a transistor with a multimeter (diode test) to determine if it is NPN or PNP.
Post the schematic somewhere for us to go and see it. |
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tim
Mad Scientist
198 Posts |
Posted - Dec 15 2006 : 2:03:49 PM
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| the pnp is the 2n5401 but the other with the number i cant locate i think is npn and there burnt. |
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tim
Mad Scientist
198 Posts |
Posted - Dec 15 2006 : 2:06:30 PM
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| this inverter im working on just wont start up i substituted the supposed npn and still wont start , and changed all the ics few diodes and few zenars. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Dec 15 2006 : 3:48:23 PM
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| Can't you get a service manual or schematic for it? |
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Topic |
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12/120V inverter again
