Stimulus test gear

couple the calibration signal (or some other square wave) to the probe tip through an apropriately sized resistor.

:There is this digital scope sold by ABI that is called a circuit :master. It does a number of things but one thing that seems unique is :that it applies a DC current to a circuit while at the same time :measuring the response. It is designed to apply this to a live :digital circuit, with power on. This is mostly used on digital :circuits. The idea is if you are measuring a circuit with 0VDC you :can determine if it is short or open and a number of other things. It :measures the response and shows it, along with the voltage measured. :Is anyone familiar with this technique and can someone explain a way I :can do the same thing using a regular scope? What do I need as a :source? I think there is a little more to it then just using my bench :power supply as the source. Is there any other gear that uses this :technique? : :Thanks :Russ

Seems to me to be a CRO with integrated digital voltmeter and function generator and some clever software to bring the functions together for ease of use.

By the look of it it isn't going to be cheap.

You must be very careful when doing that, many of today's circuits operate with components at a very low voltage level as their max voltage. Applying DC voltage to determine if a reference point is being pulled to common or just simply opened could cause damage.

I guess you could work with a 1.5 volt DC reference via a resistor. I would suggest a R of 1 Meg. is using your scope. This should be sufficient to determine is a circuit is being pulled low or is simply opened.

Even with DMM's in the diode mode, many of them apply 2 or more volts to the probes and normally use a 2k Scale as a 2.000 volt scale. This usually shows the Forward voltage of the diodes recognized in the field on low/medium voltage diodes.