USB-6008: in-line/serial connection of analog output channels?

[rub1]

Hi folks,

I want to use the USB-6008 to control a pump. Its stroke volume is regulated in proportion to the amplitude of an analog signal, in the range 0-10V.

Since there are two analog output channels at the USB-6008 each being limited to 5V, the idea is to chain up both channels (in-line), such that the resulting output is the sum of both ports. Is this possible?

In my idea (see attached drawing) I would need to connect one channel with the ground of the other channel. This is based on the assumption that the ground channel is basically the same as the negative pole to the output channel and each channel has its own ground/counter pole.

However I am not sure if this is correct. Maybe this is wrong and all ground channels are internally connected!?

Do you see another/better way to solve this?

I appreciate any help. Thank you!

[AnalogKid2DigitalMan]

The grounds are internally connected so that approach won't work.

You could google "non-inverting amplifier" using an op-amp and a voltage gain of 2.

There are also off-the-shelf modules than will take a 0-5V input signal and produce a 0-10V output signal. Dataforth's DSCA model line is one of many examples:

http://www.dataforth.com/catalog/pdf/dscaintro.pdf

-AK2DM

[rub1]

Thanks AK2DM,

I was hoping for a solution without additional accessories, but I guess I will (have to) check out those amplifiers.

Thanks again,

rub1