Search found 341 matches
- Thu Dec 23, 2004 10:34 am
- Forum: General Discussion
- Topic: Electromagnetic physics question
- Replies: 41
- Views: 15150
Re: Electromagnetic physics question
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by jwax: steven, apples and oranges. The DC system was designed for DC. Had it been designed and built for AC, the insulation would have been appropriate for AC, and efficiency is ...
- Wed Dec 15, 2004 6:42 am
- Forum: General Discussion
- Topic: need transistor help...
- Replies: 15
- Views: 5901
Re: need transistor help...
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by dacflyer: david >>>i have the base connected to a 10k resistor connected to the output of a 4017 emitter to the led.other lead of led to gnd. and the base to B+ 12v i belive tha...
- Fri Dec 03, 2004 2:51 pm
- Forum: General Discussion
- Topic: passive integrator design
- Replies: 4
- Views: 2248
Re: passive integrator design
Let's call the first Resistor R1, the first capacitor C1, etc. BTW, you can get the same amount of filtering, but faster settling, by making R2=100k and C2=10nF.<p>For the analysis, assume that you have very low ripple on C1 and C2. For analyzing the voltage on C1, we can then say that no current fl...
- Mon Nov 29, 2004 10:29 am
- Forum: General Discussion
- Topic: Universal Shift Register 74LS194
- Replies: 2
- Views: 1614
Re: Universal Shift Register 74LS194
The 74194 maximum clock frequency is a minimum of 25MHz (read the datasheet again). It will run at any arbitrarily low frequency. You should be able to use it to accomplish what you want.
- Sat Oct 16, 2004 8:09 pm
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
Yeah, I think we pretty much beat this to death. I am posting the circuit I said I had that uses a diff amp of a different sort, along with waveforms. Note that the uotput is inverted relative to the input. http://s02.imagehost.org/0525/0-2_amp_waves.GIF http://s02.imagehost.org/0525/0-2_amp_current...
- Sat Oct 16, 2004 6:24 am
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
Fred, I agree with all that. I just don't understand completely what Yigiter is trying to do (and I'm not sure he does). In this thread, I was guessing that he was trying to charge a car battery, and he wanted to use the car GND as GND for his controller (not to imply that he couldn't use +12V inste...
- Thu Oct 14, 2004 1:29 pm
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
Fred, I could sim that, and I'm sure it will look fine, but here's a quote from Yigiter: <blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>i think i can not do this. because my grounded load is a "car battery" so i can't connect the posit...
- Wed Oct 13, 2004 12:00 pm
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
Fred, can you post a complete schematic? I tried to duplicate your schematic, and I still get an oscillator, but not with the characteristics you mentioned. I'm not too surprised, because the oscillation frequency will wind up being a function of The Ft of the transistors, the beta of the transistor...
- Tue Oct 12, 2004 12:33 pm
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
If you wind up with a lemon, make lemonade. <p>A cursory look at MJ2955 vs MJE2955 datasheets looks like the differences are in package and power dissipation.
- Tue Oct 12, 2004 8:51 am
- Forum: General Discussion
- Topic: PET DOOR auto-gatekeeper
- Replies: 15
- Views: 6591
Re: PET DOOR auto-gatekeeper
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Dean Huster: If the cat's obviously old enough to go out on dates by him/herself, why the importance of the curfew? Or is it a weather thing?<p>Dean <hr></blockquote> He'll want...
- Tue Oct 12, 2004 6:24 am
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by windmiller: RonH:<p>Thanks for your fascinating reply suggesting a comparison of an actual circuit build performance against a circuit simulation performance.<p>I am setup to bu...
- Mon Oct 11, 2004 6:56 am
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by windmiller: RonH:<p>Congratulations! You are my first literary critic as an electronics writer wannabee.<p>I've built a number of circuits like this and haven't smoked one yet. ...
- Fri Oct 08, 2004 1:46 pm
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
I don't like to be critical, but I also hate to see a guy burn up his parts. There are several problems there:<p>1. The loop gain is way too high (with no compensation), which will cause the circuit to oscillate. 2. There is no current limiting through Q1 and Q2.<p>I can post a circuit that uses a h...
- Fri Oct 08, 2004 7:26 am
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by windmiller:
RonH:<p>NICE drawing!<hr></blockquote>
Thanks! Linear Technology's <p>SwitcherCAD III.
RonH:<p>NICE drawing!<hr></blockquote>
Thanks! Linear Technology's <p>SwitcherCAD III.
- Thu Oct 07, 2004 10:19 am
- Forum: General Discussion
- Topic: Current source
- Replies: 64
- Views: 29208
Re: Current source
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by yigiter: RonH: i want to control that current with a micrprocessor controlled DAC. i will use a voltage divider to divide voltage and a comparator to compare it with my referanc...