Yes, yes, that's the circuit configuration I endorse Professor. I'll say more later.
Thanks, EMD. An interesting circuit config to be sure. I have gone back to this configuration this morning, at home using my PS and ATTEN DSO. Requires low input current (8 mA) compared to config with 2 LED's (22mA) -- where current is measured using the PS and Vin = 1.51V. I also added a cap (221 pF) across L1 as I have tried this lately, making a tank circuit out of the L1 leg. This does not increase the input current, so Pin stays the same, but the Pout curve shows greater 1-cycle area (integrating Pout with respect to time, giving Energy) -- which indicates that Pout increases as the cap across L1 is added. I find that interesting. I should also note that using the 1X probe causes a change in brightness of the LED... I believe this may be due to the capacitance of the probe itself. Brightness change occurs whether the probe is hooked to the DSO or not. My next step was to measure the Cap of the probe itself -- 154 pF at 1X, about 100 pF at 10X. (Probe left open-ended.) I found that using the scope probe at 10X solves the problem, that is, the brightness of the LED does not change noticeably with the probe set at 10X, when the probe is connected to the circuit. ANOTHER important observation (IMO) regarding reliable measurements -- the parameters of the scope probes themselves!
« Last Edit: 2011-03-29, 19:56:46 by PhysicsProf »
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