Electronics Forum / Design / February 2005

"Rotary Inverter:
In a rotary inverter, DC electricity input powers a DC motor that turns
an AC generator. Rotary inverters are reliable and produce a pure

The last couple of times I've tried to access Opencores, all the links
hang- I don't even get timeouts. I don't seem to have this trouble with
other sites- any suggestions? (using Firefox).
Paul Burke

I bought a transformer (Signal Transformer model st-6-48, 24VAC@0.8A,
parallel connection). I needed 24vdc to drive the coil of a relay. I thought
24vac after rectification and filter it should go to 30vdc so a 24vdc (7824)
regulator should be right. Well... the voltage at the ...

I guess we would be looking for breathing interruptions.  So,
something around the chest?  Looking for absence of change?
Seems like something short of a hospital sleep study is needed, at
least as a screening device.

I am at the design stage of a visual effect which will comprise 25
squares, each with a red, green & blue LED, driven by a
microcontroller to achieve different colour mixes.
Initially, I am thinking of connecting the LEDs in a "row/column"

I search the best structure about an amplifier that can perform:
* a slew rate of 1000 V/µs
* an output that can swing between +/- 50V
If someone has some suggestion or some schematic, it would be great.

Does anyone have an idea for a low
voltage threshold circuit that switches
from its Low (Off) to High (On) state (or vice
versa) upon an input voltage reaching a

     Title: DFT Manager
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Wondering if such a device exists. If this is the wrong area, please
point me in the right direction.
I have multiple key fobs on my key chain (for car, open home door, etc)
and I was wondering if there is a product that is a learning key fob so

i'm trying to design a circuitry which will trigger a response when the
temperature sensors register a particular temperature.
Problem: I'm not exactly sure what should be in the circuit. CAN ANYONE
HELP ME?

I have a Marconi FM signal generator, model TF 2013, that was designed
for cell phone testing. The frequency range produced is 800-960MHz.
Can someone tell me how feasible it would be to halve the above range
to 400-480MHz, perhaps by bypassing one of the mutiplier stages?

I have seen various postings about doing SMD prototyping with very
fine point irons and solder wick for cleanup, but I would like to try
hot air.  But I don’t want to invest in a several $k professional hot
air SMD rework station.  I just want to stick down a few SOIC-8

I am looking for
- a microcontroller (single chip, no separate memories)
- fast (50..100 MIPS would be nice, more is better)
- reasonable amount of memory (at least 16k FLASH code, 16k RAM)

Why such insistence on a UPS having a "pure" sinewave vs any other sort of
output wave form such as square wave?

... is now available for free download as
http://www.tinaja.com/glib/extract1.pdf
It is on programatically xtracting text and content from Acrobat .PDF files.
Sourcecode is separately available as