Re: "Singing Arc" Project

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "robert heidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-desertgate-dot-com>

You want Hi-Fi...... Yes you do nead help...... Lotttttts of help
    Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Wed, 11 Sep 2002 21:11:05 -0600
> To: tesla-at-pupman-dot-com
> Subject: "Singing Arc" Project
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Wed, 11 Sep 2002 21:12:39 -0600
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <dhmccauley-at-spacecatlighting-dot-com>
> 
> 
> Currently working on my singing arc project.  Here is my status so far:
> 
> http://www.spacecatlighting-dot-com/teslacoil6.htm    (webpage)
> 
> 1.  Need to create a DC power supply.  Will use 115VAC mains, bridge
> rectified with about 16000uF, 450V smoothing capacitor
> 
> 2.  Singing Arc requires PWM modulation of my FET gate drivers for low-level
> topology.  This will be accomplished by using my existing TL494 PWM
> Controller IC on both my
> SSTC#1 and SSTC#2 as seen at http://www.spacecatlighting-dot-com    To
> accomplish this, the audio signal will need to be scaled and fed into my
> TL494 Feedback (comparator) input which requires a 0.5VDC input for 95% duty
> cycle and a 3.5VDC input for 0% duty cycle.  I will choose the midpoint (2
> VDC) to be the bias point for my feedback input, or otherwise with no audio
> input, the PWM controller will output approximately 50% duty cycle.
> 
> My audio source will be a broken DVD player (only reads DVD's about 50% of
> time and CD's about 90% of time).  I will use the line-level audio output
> which has maximum value of 2 Vrms operated into a 50k impedance (nominal
> output impedance is 10k)  2 Vrms is about 5.6V peak-peak so this will need
> to be scaled to a 3.0V peak-peak signal (0.5V to 3.5V duty cycle adjust
> voltage as in last paragraph) centered about a 2V bias point.  The following
> circuit illustrates my audio pre-amplifier:  Single-power supply rail is
> used since that is currently the only available Vcc.
> 
> http://www.spacecatlighting-dot-com/audioscale01.pdf
> 
> 
> If anyone has time, please look at my circuit and see if there is anything
> you would change, add, or delete.  All comments appreciated.
> 
> Thanks
> 
> Dan
> 
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