Re: inverting photo detector polarity on a microscope

Posted by Edward Allgeyer on
URL: http://confocal-microscopy-list.275.s1.nabble.com/inverting-photo-detector-polarity-on-a-microscope-tp7588654p7588657.html

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Hi Mike,

I have no commercial interest in either of the things I'm going to mention
but they maybe of interest to you.

First, there is a California based company, Pulse Research Lab, that sells
a selection of high speed off the shelf comparators/sine wave converters
that I've had success with for similar purposes. Their comparators are
fairly forgiving with what you connect as the input and you have a number
of options for the corresponding output. You can browse their selection
here:

https://www.pulseresearchlab.com/collections/comparators-sinewave-converters-1

I'll also mention that on their comparators they have preset thresholds but
you can also set an arbitrary threshold by applying a DC voltage to the
complementary input if you want to.

Second, Picoquant also sells a few inverters and adaptors that might work
for you. Specifically the SI100 is a passive inline pulse inverter and
might work for your application. You can browse their adapters, splitters
and cables here:

https://www.picoquant.com/products/category/accessories/adapters-splitters-cables-various-accessories-for-photon-counting-setups

Hopefully this helps. Again, no commercial interest in either of these
companies. Just thought I'd mention them as possible options.

Best,
Ed

On Wed, Sep 5, 2018 at 12:58 PM Michael Giacomelli <[hidden email]> wrote:

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> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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> *****
>
> Hi,
>
> I would like to test out a new detector module in a commerical Olympus
> confocal body.  Unfortunately, the detector uses an inverting amplifier
> (0->-1 V), while the Olympus assumes a non-inverting transimpedance
> amplifier (0->+1 V).  I've spoken with them and there is no way to change
> the A/D configuration on this specific model, and so I cannot use the
> detector as is.
>
> Is there a commerical solution available for adapting something like this?
> I would like to avoid having to design and breadboard an inverting buffer
> amplifier if I can avoid it.
>
> Thanks,
> Mike
>