[sdiy] converting a 10v p to p to a 0-5 volt signal

[Dan Snazelle]

with this 2 diode method (which everyone recommends) do the diodes end up CLIPPING the waveform?
one thing i really want to watch out for is changing the shape of the wave

this is why maybe David's method of going 1vptop is a good idea.

however i think i would need some heavier boosting on the way out because when i have tried such a small to PtoP i have gotten nill on the output.





----------------------------------------
> From: jerryge at cableone.net
> To: synth-diy at dropmix.xs4all.nl
> Subject: RE: [sdiy] converting a 10v p to p to a 0-5 volt signal
> Date: Wed, 20 May 2009 15:37:51 -0500
>
>
> <
> actually being one diode-voltage-drop below zero rather than zero.>>
>
> A good protection technique uses a current limit resistor followed by two
> diodes one the + voltage the other to the - voltage Followed by a Second
> current limit resistor. The voltage at the Diodes can run from ~ .6 volts
> above and below the power rails but the second resistor limits the current
> so that the on chip input protection can clamp the .6 volts at very low
> current without being damaged.
>
>
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl]On Behalf Of Adam Schabtach
> Sent: Wednesday, May 20, 2009 12:57 PM
> To: synth-diy at dropmix.xs4all.nl
> Subject: RE: [sdiy] converting a 10v p to p to a 0-5 volt signal
>
>
> Aside from range scaling, I'm still looking for a good protection circuit
> for microcontroller inputs. I want hard clipping at 0V and 5V to protect the
> micro. I've seen various solutions described on this list, but when I put
> them into SPICE I have always found some flaw, such as the lower limit
> actually being one diode-voltage-drop below zero rather than zero. I'd be
> very happy if I could find some nice solution to this problem so that my
> micro-based modules can protect themselves rather than having to depend upon
> my poor memory to avoid being subjected to unacceptable voltage ranges. :-)
>
> Or, putting it another way: converting 10Vp-p to 0-5V with op-amps is a fine
> solution, but as soon as you add two 10Vp-p signals together (e.g. mixing
> two LFOs) the input range can easily exceed 10Vp-p and hence the output
> range will also exceed 0-5V.
>
> --Adam
>
>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl
>> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of
>> Jason Proctor
>> Sent: Tuesday, May 19, 2009 6:50 PM
>> To: synth-diy at dropmix.xs4all.nl
>> Subject: Re: [sdiy] converting a 10v p to p to a 0-5 volt signal
>>
>> i did exactly this for my Arduino module. it bidirectionally
>> interfaces a +/-5v signal to the micro's 0-5v range.
>>
>> turned out to be pretty easy - on the way in, chop the signal
>> in half, and bias with +2.5v. then reinvert. on the way out,
>> do the opposite. 1 dual opamp each way.
>>
>> lmk if you want the details.
>>
>> (i should also thank Tom Wiltshire here for his help getting
>> me off the ground with this stuff.)
>>
>>
>>>tonight i was looking at my scope
>>>
>>>Checking the input into a circuit that was only able to take
>> 0-5 volts
>>>
>>>Sure enough, the signal was between 0 and 5 but the sawtooth
>> was clipped.
>>>
>>>So i am looking for a input block that can take either
>>>5vp to p or 10v p to p (or any synth signal)
>>>and spit it out as a 0-5 signal without squaring the top.
>>>
>>>
>>>anyone know of a good circuit for this?
>>>
>>>thanks
>>>
>>>_______________________________________________
>>>Synth-diy mailing list
>>>Synth-diy at dropmix.xs4all.nl
>>>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
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