SDG Electronics PicoScope 5000 Series Demonstration

Steve from SDG Electronics provides us with two demonstrations using a PicoScope 5000D series to validate the operating characteristics and power efficiency of an AC LED lighting controller.
He then illustrates the integration and debug of an RS-485 control link between a humidity sensor and a bathroom extractor fan.
SGD Electronics: / sdgelectronics

[@robertlawson4295]

Excellent!! Just bought this PicoScope model recently but haven't yet had a chance to get to the project I will be using it for. Thanks for the sneak peek ... looking forward to hands-on sessions.

[@SaeligCoInc]

Terrific scope!

[@windward2818]

On some power project boards, like a small Aux off-line fly-back switching supply for example, many times we would like to monitor currents on the PCB, but if I use a traditional current probe I have to introduce a loop to clamp around, as you did in the video. This creates two problems; first I must break into a circuit, and then introduce a loop (which may introduce unacceptable inductance). What I would like to do is on my designs that are not board space critical (like a cell phone), is to provide place holders on the board to accommodate either an 0805 zero ohm device or a 10mOhm non-inductive current sense resistor for circuits that operate in a current mode. I want to make my own active differential probe that has a PCB with a tapered nose having two very short leadd spaced so that I can solder the probe leads to each side of the sense resistor (within 10mm at most). The probe would be powered by four 9V batteries for +/- 18Vs input with regulated LDOs for +/- 15V. The probe would be floating with input using INA849 (instrumentation amplifier) and output using OPA191 to drive a short BNC coax. After I complete my testing I would replace the 10mOhm sense resistor with a zero ohm jumper. For layout I can put the 0805 place holders where they are most likely needed to monitor current. So the thinking is to introduce an accurate small current sense resistor without adding too much resistance or too much inductance which may influence the circuits operation. I think for most of my needs a probe bandwidth of 5 MHz (INA849) should work. For higher bandwidth I would have to modify the input stage. I do I lot of evaluation with semiconductor vendors evaluation boards, and usually I am disappointed by how few and poorly designed the test methodology is (test point design, scope connection, etc.) given the expected waveforms and potential high frequency content (which are well understood given the design is by the chip maker).