| Products > Test Equipment |
| Show Us Your Curve Tracer |
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| EinErik:
With this new tracer, compared to my old lockyZ, this one is definitely better with no doubt >:D https://www.diyaudio.com/community/threads/new-tracer-is-coming.379759/page-5 |
| RichardM:
I would love to make this version of the curve tracer. I don't suppose you are willing to share the PCB/Scematics ? I have the ELV articles. Regards Richard |
| Electron123:
What's the difference between a "transistor curve tracer" and a more basic octopus version (like this https://www.qsl.net/kd7rem/pdf/octopus.pdf)? I know the fancy versions have more features, but are they both able to test the same components? Or is the basic one not able to test transistors? |
| Cubdriver:
--- Quote from: Electron123 on August 23, 2022, 01:31:22 am ---What's the difference between a "transistor curve tracer" and a more basic octopus version (like this https://www.qsl.net/kd7rem/pdf/octopus.pdf)? I know the fancy versions have more features, but are they both able to test the same components? Or is the basic one not able to test transistors? --- End quote --- A transistor curve tracer allows you to characterize the transistor or other device - see how it behaves under different drive conditions. The octopus is more a go/no-go thing that tells you it works, but not much more. In this image of a curve tracer, each slanted line represents a different base current; the sweeps are the collector current as Vce is increased and decreased at each base current step. In this image, the vertical scale is 5 mA/division, and the horizontal is 5 V/division. The base current steps are 0.01 mA each. Note that it has two sockets and the big toggle switch, it is set up to permit two transistors to be connected and by flipping the switch back and forth you can see how closely they are matched. -Pat |
| Cubdriver:
To elaborate on how the curve tracer works, it applies a base current (or gate voltage if testing a FET), then sweeps the C-E (or S-D) voltage from minimum up to whatever max you've set. It then increments the base/gate drive by the step interval and sweeps the C-E/S-D voltage back down to zero. Increments the drive again, repeats the low-to-high sweep, increment again and high-to-low. Lather, rinse, repeat until the desired number of steps have been generated. The beam on the screen thus traces out the current through or voltage across the transistor under test. The curves for a PNP device are similar, but start in the opposite corner of the display as the polarities are reversed from those of an NPN (top right for PNP, bottom left for NPN): Curve tracers can also characterize things like diodes and the strike voltage of neon lamps (sometimes used as voltage limiters/regulators). In this instance, the device in the curve tracer is a color-changing LED, and the photo was taken as it was lighting two of its emitters to get a blended color. Each of the colored LEDs inside has a slightly different forward voltage, thus the dual curves with slightly different voltages and currents, and the jumping between the two curves is caused by the internal IC in the LED switching the two different LED dies on and off alternately: -Pat |
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