A transistor can switch a load using a separate base-drive path. With enough drive, a BJT enters saturation and its collector-emitter voltage becomes small.
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SUPPLY5.00 V
CURRENT5.00 mA
OUTPUT3.90 V
TIME0.00 s
Live curve
Calculated outputSource waveformMarker = current time
A transistor can switch a load using a separate base-drive path. With enough drive, a BJT enters saturation and its collector-emitter voltage becomes small.
1. Set up the experiment
Change base drive from zero upward. Observe cutoff, active operation and the load-limited saturation region.
2. Connect the result to the equation
I_load ≈ (V − V_CEsat)/R_load at saturation
Change one parameter at a time and keep the others fixed. Read the signed output and current, then use the curve to distinguish a steady relationship from a changing transient.
Initial supply
5.00 V
Initial current
5.000 mA
Initial output
3.900 V
3. Notice the limits
A base resistor controls input current. A motor or relay also needs appropriate protection for inductive switching; this resistive-load lab omits that transient.
Circuit reference diagram
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Why it’s here
Electronics 101 makes a component change visible: an altered resistance changes a current, a capacitor changes a delay, and a sensor changes a decision. The course guide links each concept to its experiment.
Open Ohm’s law and predict the effect of doubling the voltage.
Change the control and compare the ammeter, curve and equation.
Try RC charging and use the time constant to explain the curve.
Return to the course guide to choose the next experiment.
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Yes. The course guides and workbenches run on NavSprout.
Are these circuit simulations exact?
They are analytic teaching models: ideal sources and switches, fixed diode drops, simple BJT gain and saturation, exponential RC behavior, and illustrative sensor curves. They are not a SPICE solver or construction verification.
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Which current direction is shown?
Moving markers represent conventional current, not electron drift. Their motion is illustrative and is not a measurement of charge velocity.
Model references and scope
Original NavSprout lessons use standard lumped-circuit relationships and explicitly simplified component models. Diagrams explain teaching topologies, while the breadboard probe explains socket continuity. The workbench is not a verified physical assembly plan.
