Recent content by crono1009

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    Using a 555 timer as an analog frequency divider?

    Yeah, I figured as much. I've been simulating with only one input frequency, I could see how this would be cumbersome. Thanks for the tip!
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    Using a 555 timer as an analog frequency divider?

    Hey guys, I'm trying to build a circuit where I can put in an analog signal (my voice) and have it output the same signal with a much lower pitch (speech synthesizer). Is there any way I could do this with primarily a 555 timer? I'm able to pulse width modulate the analog signal, but I...
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    VHDL code - write to a binary .dat file

    I'm attempting to write some simulation VHDL code that will be able to write the output of my simulation as a single string of binary values in a .dat file. So far I've used both the textio and std_logic_textio libraries to write the signals to a .txt file as text. Is there a library I can...
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    Kit for Art of Electronics (Horowitz and Hill)?

    If you want to simulate digital circuits I recommend logisim; it's a free, very low resource, simple, logic simulator. http://ozark.hendrix.edu/~burch/logisim/
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    Easily modifying BJT parameters in LTSpice?

    Actually vk6kro I have another question about LTspice if you don't mind. Let's say I created put a generic npn transistor in my circuit. Then I created a .model for that transistor for example, .model 2N3904-95 NPN(Bf=95). Will LTspice insert its own default values in for all of the other BJT...
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    Easily modifying BJT parameters in LTSpice?

    Thanks! That worked perfectly.
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    Easily modifying BJT parameters in LTSpice?

    I've created a multistage amplifier in LTSpice IV and want to use actual measured hfe (Beta) values for each of the transistors, though I can't find an easy way to modify them. I could modify their library values in notepad, but I am using the same transistor model for a few of the stages and...
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    Modeling I-V Characteristics in LTSpice

    Thanks for the tips. I am happy with my cut-in voltage, around 0.7V where it should be. Though I'm having another dilemma, I want to display my breakdown voltage characteristics also. The breakdown voltage of my 1N4148 diode is 75V. So I swept my DC voltage source from -100V to +2V in 0.01V...
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    Modeling I-V Characteristics in LTSpice

    I'm trying to model the I-V characteristics of a few diodes in LTSpice. Though doing the DC sweep I have in the picture doesn't seem to give me what I want. I'm sweeping from -80V (It's breakdown is 75V) to 2V, in 1V increments. What kind of simulation do I have to run across the diode to get a...
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    Exploring Distributed Element Models for Circuit Designers

    I would definitely check out "The Art of Electronics" by Horowitz and Hill, it's the best circuits book I've read. It's slightly dated (second edition), though still completely relevant. Keep in mind the third edition may be coming out as early as January...
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    Topic about autoroute in PCB designing

    It really depends on the scope of the board and the software you are using. All the free PCB layout software I have used have rubbish auto-routing features. Though more expensive software such as PADS have respectable auto-routing features that you could go back and correct any problems you see...
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    1000Base-T vs 1000Base-X (Copper vs Fiber) design guidelines

    While looking for space saving solutions for my gigabit ethernet board I found SFP transceivers. Does anyone have any experience with these? Can one 1000BASE-T SFP transceiver replace the RJ45, Magnetics, and PHY on my board? Thanks, -Kevin
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    1000Base-T vs 1000Base-X (Copper vs Fiber) design guidelines

    I'm currently designing a dual port 1000Base-T Gigabit Ethernet circuit card. My problem is that I do not have much space to work with on my board and the dual port RJ45 Magjack is taking up a ton of space. To save space I've been looking to switch to a fiber-optic system with much smaller...
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    Micro-controller Programming Problem - Assembly

    Homework Statement I am writing a program to loop (rotate) two lit LEDs through eight LEDs on my board. For Example: 11000000 01100000 00110000 00011000 00001100 00000110 00000011 Where the ones are lit LEDs and the zeros are non-lit LEDs. It is supposed to loop forever. Homework Equations...
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