SSG smooth output voltage range

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ketem13
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SSG smooth output voltage range

Post by ketem13 »

Build from CGS SSG schematics using +-12V power rails.

I patched the smooth cycle out into the smooth section In and measure the voltage at the Smooth out using a multi-meter. The result shows a voltage between 0V and +4V~ . Is it how it should be? I was thinking it suppose to cycle between negative and positive voltages? also - 4V seems too low..
Can someone confirm the voltage range of the smooth output?
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guest
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Re: SSG smooth output voltage range

Post by guest »

yes, that sounds about right. the cycle out is a comparator with thresholds around 0V and 5V.
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ketem13
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Re: SSG smooth output voltage range

Post by ketem13 »

guest wrote: Fri Jan 14, 2022 3:20 pm yes, that sounds about right. the cycle out is a comparator with thresholds around 0V and 5V.
It written "+/- swing close to the power supply supply voltage"
This is why I though my 0V-4V swing is a mistake somehow..
Screen Shot 2022-01-15 at 9.15.35.png
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Re: SSG smooth output voltage range

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the cycle out is +/-12V, but the smooth out is 0-5V when driven by the cycle. to be more specific, on the schematic what is called OUT will go 0-5V when CYCLE is used to drive input.
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ketem13
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Re: SSG smooth output voltage range

Post by ketem13 »

guest wrote: Sat Jan 15, 2022 2:23 am the cycle out is +/-12V, but the smooth out is 0-5V when driven by the cycle. to be more specific, on the schematic what is called OUT will go 0-5V when CYCLE is used to drive input.
The fact I'm reading only 0v - 4V swing on my multimeter could be because my multimeter is not precise enough? or it might be that the original design were running on +-15V so I have 1V less in swing?
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Re: SSG smooth output voltage range

Post by guest »

5V is just an estimate here, it depends upon saturation voltage of the 3900 and input diode drops, etc. basically, the 3900 switches when the current going into its input pins are equal. on the one side, thats OUT voltage minus a diode drop (internal to 3900) divided by 470k. the other side is 1M to 12V minus same diode drop, and then either plus or minus 12V with the 2.2M, depending upon state.
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cygmu
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Re: SSG smooth output voltage range

Post by cygmu »

And of course when used as a slew, i.e. following the input rather than patched to cycle, it can follow voltages well outside the cycling range, including negative voltages.
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