PickettLabv2.1

Virtual electronics lab

🏠

Virtual Electronics Lab — Build & Test Circuits Online

🖥️ Best on Larger Screens

PickettLab is a virtual electronics workbench with drag-and-drop components, a multimeter, and an oscilloscope. It works best on a tablet or desktop where you have room to build circuits.

You can still use it on this device, but the experience will be limited.

📦 Components

Power
🔋
DC Source
⚡
AC Source
🔋
Battery
⏚
Ground
Passive
▬
Resistor
||
Capacitor
⦚
Inductor
Semiconductors
▶|
Diode
NPN
Transistor
💡
LED
Output
💡
Light Bulb
⚙️
Motor
🔊
Buzzer
Control
👆
Push Button
⚡
Switch
🎚️
Potentiometer
🔌
Fuse
⊙
Junction
〰️
Wire
No component selected 💡 Drag from a terminal dot to another to wire · press a probe, then tap a terminal to measure
🔌

PICKETTECH PS-24

DC bench supply · 0–24 V

5.0 V
Voltage Control
📊

PICKETTECH DM-10

Multimeter · V A Ω ♪

0.00
Voltage (V)
Press a probe, then click a part on the bench
📈

PICKETTECH OS-20

Oscilloscope · 1 channel

Ready
Components: 0 (0 wires)
⬡ PICKETTECH OSCILLOSCOPE

Guided experiments

Ten short experiments. Each one loads a ready-made circuit onto the bench and tells you what to measure and what you should see.

EXPERIMENT 1

An LED needs a resistor

Without a resistor an LED draws far too much current. The resistor sets it.

  1. Load the circuit and press Simulate.
  2. Read the current label under the LED. Or set the DM-10 to A, press the red probe and tap the LED.
  3. Change the resistor to 470 Ω and watch the current fall.
I = (Vsupply − VLED) ÷ R
At 5 V with 220 Ω you should read about 13.6 mA. A bigger resistor means less current and a dimmer LED.
EXPERIMENT 2

Voltage divider

Two equal resistors split the supply in half. This is how sensors and pots turn position into a voltage.

  1. Load it and press Simulate (the PS-24 is set to 9 V).
  2. Set the DM-10 to V. Press the red probe and tap the left end of R2, then tap the ground symbol.
  3. Change R2 to 20 kΩ and predict the new reading first.
Vout = Vin × R2 ÷ (R1 + R2)
You should read 4.5 V. With R2 = 20 kΩ it rises to 6 V.
EXPERIMENT 3

Series resistors

In series the same current flows through every part, and the resistances add up.

  1. Load it. With the simulation stopped, set the DM-10 to Ω: red probe on the left end of R1, black on ground.
  2. Press Simulate. Set A and tap either resistor with the red probe.
  3. Set V and measure from the left end of R2 to ground.
Rtotal = R1 + R2 · I = V ÷ Rtotal
You should see 3 kΩ, 3 mA, and 6 V across R2.
EXPERIMENT 4

Parallel resistors

In parallel every branch gets the full voltage, and the total resistance falls below the smallest resistor.

  1. Load it. With the simulation stopped, set Ω and put the probes on the two junction dots.
  2. Press Simulate and read the current label under each resistor.
  3. Add the two branch currents and compare with the supply current.
1 ÷ Rtotal = 1 ÷ R1 + 1 ÷ R2
Total resistance is 667 Ω. R1 carries 6 mA and R2 3 mA: 9 mA from the supply.
EXPERIMENT 5

Watch a capacitor charge

A capacitor charges through a resistor along a curve. The time constant τ tells you how fast.

  1. Load it: the scope is set to Roll at 500 ms per division, watching the capacitor.
  2. Press Simulate and watch the trace climb in real time.
  3. After 1 s (two divisions) read the voltage. Stop and Simulate again to replay.
τ = R × C = 10 kΩ × 100 µF = 1 s
After 1 s the capacitor is at 63 % of 5 V, about 3.2 V. After 5 s (5τ) it is about 99 % charged.
EXPERIMENT 6

AC on the oscilloscope

An AC source swings positive and negative. The scope draws it as a sine wave.

  1. Load it and press Simulate (5 V peak, 50 Hz).
  2. The scope shows 2 V per division and 5 ms per division.
  3. Select the AC source, change the frequency to 100 Hz and watch the waves bunch up.
Period T = 1 ÷ f
At 50 Hz one cycle takes 20 ms, so each wave spans 4 divisions. The scope reads about 10 V peak to peak; the DM-10 on V reads 3.54 V rms (5 ÷ √2).
EXPERIMENT 7

Switch and bulb

The simplest control circuit: an open switch breaks the loop, a closed one completes it.

  1. Load it and press Simulate.
  2. Click the switch and press Space to open and close it.
  3. Stop, set continuity, and put a probe on each end of the switch. Try it open and closed.
Open switch = open circuit
The bulb lights only when the switch is closed. Continuity beeps only when it is closed.
EXPERIMENT 8

Blow a fuse (safely)

A fuse is a deliberate weak link. Too much current and it opens the circuit before anything else is damaged.

  1. Load it and press Simulate (9 V, 47 Ω, 100 mA fuse).
  2. Watch the status bar when the fuse blows.
  3. Stop, change the resistor to 220 Ω, select the fuse, press Reset Fuse, then simulate again.
I = V ÷ R = 9 V ÷ 47 Ω
About 190 mA tries to flow, so the 100 mA fuse blows. With 220 Ω about 41 mA flows and it holds.
EXPERIMENT 9

Push to light

A push button only closes while you hold it: the basis of doorbells, keyboards and PLC start buttons.

  1. Load it and press Simulate.
  2. Click and hold the push button (or select it and hold Space).
  3. Set the DM-10 to A and tap the LED while you hold the button.
I = (9 V − 2 V) ÷ 470 Ω
The LED lights only while the button is held, with about 15 mA flowing.
EXPERIMENT 10

A transistor as a switch

A small base current turns on a much bigger collector current. This is how a microcontroller pin drives a motor or relay.

  1. Load it and press Simulate. Hold the push button.
  2. Set the DM-10 to A. Tap the transistor's base (B) with the red probe, then tap the LED.
  3. Compare the two currents.
IB ≈ (9 V − 0.7 V) ÷ 10 kΩ
Base current is about 0.83 mA, LED current about 20 mA. The transistor is fully on (saturated): the LED's resistor, not β, sets the current.