Real-time oscilloscope view of 240V/120V split-phase power delivered to your home or RV.
This shows the actual electrical waveforms you get from ONE distribution transformer (like T1, T2, or T3). The green L1 and orange L2 are "hot" conductors that are 180° out of phase, giving you 240V between them and 120V from each to neutral (white). This is the final step in the power delivery chain - what actually powers your home, RV, or business after traveling from power plants through high-voltage transmission lines and being stepped down by distribution transformers.
Voltage Statistics & Transient History
Historical Voltage Analysis
Tracks voltage extremes, transient events, and power quality over time for equipment protection analysis.
Records maximum and minimum voltage peaks during faults, motor starts, and other transient events. Essential for sizing surge protectors, understanding equipment stress, and diagnosing power quality issues. Transient history shows how voltage disturbances propagate over milliseconds to seconds - critical for understanding why sensitive electronics fail during electrical events.
Voltage Extremes
Peak High:+170 V0.00s
Peak Low:-170 V0.00s
Max RMS:120.2 V0.00s
Min RMS:120.2 V0.00s
RMS Voltage
Transient Events
3-Phase Grid Source
3-Phase Power Generation and Transmission
Shows the 3-phase electrical power as it comes from power plants through high-voltage transmission lines.
Power plants generate electricity in 3 phases (A, B, C) that are 120° apart for maximum efficiency. This 3-phase power travels hundreds of miles on high-voltage transmission lines (69kV-765kV) to substations. At distribution voltage (typically 7200V), the three phases feed distribution transformers in neighborhoods. Each phase powers different transformers to balance the electrical load across the grid. This phasor diagram shows how the three phases relate to each other - they're perfectly balanced and create a smooth, efficient power delivery system.
Phase A: 7200V (Gray)
Phase B: 7200V (Red)
Phase C: 7200V (Blue)
Distribution Transformers
Neighborhood Distribution System
Shows how 3-phase grid power is converted to split-phase residential and commercial service.
Each distribution transformer takes ONE phase from the 3-phase grid (7200V) and steps it down to split-phase service (240V/120V). The transformer has a center-tapped secondary winding that creates two 120V "hot" legs (L1 and L2) that are 180° out of phase, plus a neutral. This gives homes both 120V (hot to neutral) for lights and outlets, and 240V (hot to hot) for large appliances like dryers and air conditioners. Multiple transformers in a neighborhood are fed from different phases (A, B, C) to balance the electrical load. The main split-phase visualization shows the output from just ONE of these transformers.
Distribution → Service
Center-Tapped Secondary
P1, P2, P3 → T1, T2, T3
Basic Parameters
Split-Phase Electrical System
Enables/disables North American split-phase visualization showing both L1 and L2 hot legs.
L1 and L2 are 180° out of phase. L1-L2 = 240V, L1-N = L2-N = 120V RMS. This is the standard residential electrical system in North America and many RV parks. Essential for understanding shore power connections and inverter systems in RVs and off-grid installations.
AC Frequency
The rate at which AC voltage alternates direction.
60 Hz = North America standard (grid power, shore power, most RV inverters). 50 Hz = European/International standard. Wrong frequency affects: AC motors run 20% slower/faster (60Hz motor on 50Hz runs slow, overheats). Linear transformers operate inefficiently, can overheat or saturate. Modern switching power supplies (look for "50-60Hz, 120-240V input") are usually tolerant of frequency/voltage variations. Old linear supplies and motor-driven devices (fans, pumps, compressors) are sensitive to frequency changes.
✓ North American Standard (120V RMS Split-Phase)
Peak Voltage
Maximum voltage amplitude of the AC sine wave.
170V peak = 120V RMS (170÷√2). Peak-to-peak = 340V. Wrong voltage causes specific failures: Low voltage (brownouts) - motors overheat trying to maintain power, contactors may not close, LED drivers flicker. High voltage - capacitor dielectric breakdown (pop/smoke), incandescent bulbs burn out quickly, electronics exceed voltage ratings and fail. Inverter components must handle peak voltages (170V), not just RMS (120V) - this is why cheap inverters fail.
DC Offset & Grounding
DC Offset Voltage
Shifts the AC waveform up or down from zero reference.
DC offset causes: Transformers saturate and overheat, AC motors experience increased vibration and bearing wear, capacitors in power supplies stress and fail prematurely. When chassis grounding is disabled, DC offset elevates "neutral" voltage - touching neutral and ground simultaneously creates shock hazard. Switch-mode power supplies may malfunction as their reference point shifts.
Chassis Grounding
Bonds the DC reference to chassis ground for safety.
Without proper grounding: Metal appliance cases become energized (shock/electrocution risk), GFCI outlets malfunction or refuse to reset, surge protectors can't function properly, static electricity builds up damaging electronics. Ground faults can't clear safely - instead of tripping breakers, current finds alternate paths through people or equipment. In RVs: chassis must bond to shore ground. Off-grid: requires proper grounding rod system and bonding of all metal systems.
Fault Simulation
Electrical Fault Types
Simulates various real-world electrical faults and load conditions common in RV and off-grid systems.
Motor startups cause voltage sags that dim LED lights, reset digital clocks, cause microwave displays to flicker. Arc faults create RF interference (affects radios, TV reception), carbonize wiring insulation, create fire hazards. Neutral loss makes 120V loads see 240V - LED drivers explode, phone chargers smoke, computers shut down on overvoltage protection. Phase imbalance causes single-phase motors to overheat, three-phase equipment to vibrate excessively. Harmonic distortion makes transformers buzz loudly, causes neutral wires to overheat even with balanced loads.
No active faults
Oscilloscope Controls
Oscilloscope Trigger Modes
Controls how the waveform display is synchronized.
No Trigger: Waveform scrolls left-to-right like analog scope without trigger. Auto Trigger: Locks display to voltage crossing point for stable view. Manual Trigger: User controls phase position to verify real-time simulation and study specific waveform points.
Trigger Level Control
Voltage level where trigger locks the display (Auto) or sets trigger point (Manual).
Auto Mode: Trigger occurs on rising edge when waveform crosses this voltage. Manual Mode: Sets the voltage reference point for manual trigger control. Range: ±100V to handle peak voltages up to 300V. 0V = zero crossing trigger. Useful for studying specific voltage thresholds, DC offset effects, or isolating fault conditions at specific voltage levels.
Adjust trigger voltage like a real oscilloscope
Manual Trigger Voltage
Set the exact voltage level for manual triggering like a real oscilloscope.
Range: ±100V to handle systems up to 300V peak. Trigger locks display when waveform crosses this voltage on rising edge. Move slider to see immediate response - proves real-time simulation. Use to examine specific voltage levels during faults, startup transients, or normal operation. Essential for troubleshooting voltage-sensitive equipment issues.
Simulation Speed Control (Logarithmic)
Controls the speed of the entire simulation relative to real-time using a logarithmic scale.
Logarithmic scale from 0.001x to 1.0x for better control at slow speeds. 1.0x = real-time speed. 0.001x = ultra-slow motion (0.1% speed, 1 rotation per 16.7 seconds) for detailed educational demonstrations. 0.01x = very slow motion for fault analysis. 0.1x = slow motion for observing transients. Most of the slider range is dedicated to educationally useful slow speeds.
Real-time Parameters
Peak to Peak
340 V
Peak-to-Peak Voltage
Total voltage swing from positive peak to negative peak.
Peak-to-Peak = 2 × Peak Amplitude. For 170V peak sine wave: 340V peak-to-peak. This represents the maximum voltage difference that can appear across a load or between measurement points.
RMS Voltage
120.2 V
RMS (Root Mean Square) Voltage
Effective voltage value equivalent to DC for power calculations.
RMS = Peak ÷ √2. This is what your multimeter measures and what device nameplates specify. Devices fail when RMS voltage is wrong: Motors rated for 120V RMS will overheat and burn out on 140V RMS, while struggling to start and running hot on 100V RMS. Heating elements produce wrong heat output (resistance heating follows V²/R). Most electronics have ±10% voltage tolerance before malfunction or damage.
Zero Crossing
0 V
Zero Crossing Voltage
The voltage level where the AC waveform crosses zero.
Should be 0V when properly grounded. DC offset or floating ground can shift this dangerous levels. When chassis grounding is disabled, DC offset directly affects zero crossing. Critical for safety - elevated zero crossing means "neutral" is no longer at ground potential.