I don't think those are available at 500mA.Use a field-effect current regulator diode! Google for the right type of device.
Alberto
How much current do you need? Keep in mind that a microamp times a megohm is a volt.the load would be in mega ohms range
He's measuring surface resistivity. Perhaps it's the Earth's surface.I'm wondering what load could survive 1.25megawatts power dissipation?
500mA current through 5MEG Ohms is 1.25megawatts.
There are probably easier ways to bore a hole through the planet.He's measuring surface resistivity. Perhaps it's the Earth's surface.
Here's a quote from the OP:The output impedance is not a measure of the voltage, it is normally a measure of the accuracy of the constant current, ie compare to a constant current source formed by a voltage source and a resistor. That would have a high voltage.
And another:my project was to construct a insulator surface resistivity meter using 4 point probe methord,
the load ranges around 5mega ohms
the load would be in mega ohms range
by Robert Keim
by Lisa Boneta
by Robert Keim