Hi, my name is Frank, I work as an automotive mechanic.
I would like to know if there is a device to move positive signals to negative, let me explain.
I have a 500 psi absolute pressure transducer, it works with 5v reference and its signal range is 500mv to 4.5v. (500mv = 0psi | 4.5v = 500 psi) (I think I can say that it operates in a 4v range, from 500mv to 4.5v, I hope that is understood), it has a response time of less than 1ms, it is from SSI Technologies.
I use this transducer in conjunction with an oscilloscope, and it has input ranges of + - 500mv, + - 1v, + - 2v, + - 5v, up to 20v.
This oscilloscope allows me to create custom probes.
By creating a custom probe for this transducer, it would operate in the +- 5V input range (-5v to +5v = 10v total reading), which would give me 40% resolution.
This is why I would want to shift the 500mv signal to -2v , and shift the 4.5v signal to +2v (still operating in the 4v range, -2v to +2v = 4v total) to get the highest resolution range.
I would use the + - 2v input range of the scope.
Is there a device in the DigiKey store that you recommend that would allow me to do this shifting? Or would I have to make one myself?
Even if it is a dimmable device, it could still operate in the -1v to +1v range (2v total), so I could make another custom probe for 250psi and still get the highest resolution.
I hope you understand what I am trying to explain. Thank you very much for your time.
I don’t know if I’m posting in the right place, or should I be posting in test and measurements? 
Gracias.
Hello Frank.
Unfortunately I cannot answer this one. One of our Engineers will take a look and come up with some kind of solution for you.
Any circuit you add to the oscilloscope input will LOWER the accuracy of the readings.
What you want to do is adjust the oscilloscope controls to move +0.5 Volt to the bottom of the screen and +4.5V to the top of the screen.
That will give you a 100% resolution view of the signal while maintaining the full specified accuracy of the oscilloscope readings.
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Hello @frank.ticlio,
Yes, we do offer devices that could perform this operation. As I understand your requirements:
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you wish to add a DC offset to the sensor’s output.
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I suspect you would like to one day change the gain e.g., so that the sensor has a 0 to 5 VDC output corresponding to a 0 to 500 psi sensor measurement.
This converter could be designed using, a precision voltage reference, and an operational amplifier. The downside is that you would need to assemble and test the device. This is not overly difficult but may be time consuming if you have never constructed electronics circuits.
As an alternative, let me show you the Cadillac. You could use this Red Lion to display the pressure directly.
Please let us know how you would like to proceed so that we may offer additional assistance.
Best wishes,
APDahlen
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It’s right. Shift the signal from 500mv to -2v and 4.5v to +2v; and using the ±2v input range of the oscilloscope, I can get 100% resolution.
I have read that it can be done with operational and a source that supplies both positive and negative voltages.
Can that device you show move the positive signal to negative? or can it only extend the signal from 0v to 5v? Is there any video of how this product works?
Thank you very much for your time
Hello @frank.ticlio,
The display would directly accept your sensor and display the value on the screen.
Lower cost devices are available if you are interested.
Sincerely,
Aaron
P.S. I may not have a complete understanding of your application. What is the end goal?
