Ayup!
In a past life I worked on the hardware and software for industrial control kit. 4-20mA, 0-10V, that sort of thing. Occasionally we'd need do linearity and hysteresis tests by feeding in a variety of 0-10V ramps and measuring the process output. I'm finding myself needing to do something similar for a VCO design.
At that place we had a fleet of Yokogawa GS210s and 7261s (precision DC voltage/current sources) which were great for this -- hook them up to a PC via USB, hook up a measuring instrument for the output, run a script on the PC to step through the various ramps. I've had a look at pricing but £1k+ is more than I'd want to spend for something I wouldn't use all that often.
I've had a dig around elsewhere and discovered the NI USB-6009 DAQ, which has two 0-5V analog outputs with 12-bit resolution. That's probably fine -- but it'd be useful to have 0-10V and bipolar (+/-5V or +/-10V) ranges too. Analog-in isn't really necessary, I have other instruments for that.
Does anyone know of something like the NI USB-6009 DAQ or the Yokogawa instruments, but with a wider output voltage range?
Output current requirement would be a few milliamps at most, to drive a varactor diode or some kind of input stage.
Update rate - once a second is fine, the settling time on the measurement will be longer.
I've thought about homebrewing something out of a bandgap reference, some 12- 14- or 16-bit DACs, an amplifier stage and a microcontroller -- but that seems like hard work I'd rather put into my fancy RF designs, if there's some off-the-shelf kit I can use instead!
Cheers
-Phil