Shop by Price
Featured Products
MSRP: $174.95
Add to cart for instant quote!
Join our Newsletter
Subtotal: $0.00

> Training > Advanced Lab Scope Voltage & Current Testing


Advanced Lab Scope Voltage & Current Testing

Your Savings:
$11.00 (10%)
California Residents: Proposition 65 Warning
Eligible for FREE Ground Shipping(Eligible for FREE Ground Shipping)

OEM flowcharts are linear documents that focus on open circuit testing. This process takes a long time, it can also be misleading because faults don't always show up under flowchart testing conditions.

The Lab Scope offers a way to measure actual circuit activity under actual operating conditions.

This manual is designed to challenge even the most experienced Lab Scope users with new techniques and tips to leverage the power of the lab scope. However, even new Lab Scope users will get what they need to take those first steps.

This manual includes numerous real-world examples, including:
- Hand held and PC based Lab Scopes
- Current probes
- Current test alternatives
- Lab Scope voltage drop tips & tricks
- Circuit access tools
- Inexpensive transducer-based testing
- Specific sensor, motor & solenoid tests

After reading this manual you will have learned new time saving combination tests and strategies for quickly pinpointing elusive faults.

This manual includes a few screen captures from the Snap-on MODIS, and a lot of screens from the Bosch mts5200, and the ATS Escope.


Table of Contents

SECTION 1 Introduction
- Diagnostic Process
- Ohm* Law
- Tools & Tests
- Lab Scope Setup
- Probes & Adapters

SECTION 2 Ignition Systems
- System ID & Test Selection
- Triggers & IC Control
- Primary & Secondary
- Current Testing

SECTION 3 Sensors
- Thermistors
- Potentiometers
- Pressure Sensors
- Flow Sensors
- Oxygen Sensors
- Speed & Position Sensors

SECTION 4 Actuators
- Relays & Solenoids
- Rotating Motors
- Stepper Motors
- Oxygen Sensor Heaters

SECTION 5 Transducers & Capacitors
- Compression Waveforms
- Vacuum & FlowWaveforms
- Capacitor Filters

282 pages, 8-1/2" x 11".




Power Side Voltage Drop Tests -- 2008 Toyota


Excerpt from ATG's manual, "Advanced Lab Scope Voltage & Current Testing"


A simple DVOM test shows source voltage, which may be low if there is a battery or charging issue, but the traditional static tests don't show you voltage dropping across unintended loads on the power side of a solenoid.


A DVOM can measure voltage drop, but won't react fast enough to give you useful tests results on a cycling solenoid.


Lab Scopes solve this problem by drawing a picture of the circuit activity over time so you can see momentary voltage drops that your DVOM would simply average. Lab Scopes are rarely used for this purpose, but they should be.


The example aboves shows the ground side voltage drop (top trace) and power side voltage drop (bottom trace) for the same solenoid event. The ground side waveform shows the effect of any resistance in the ground side, including the transistor in the controlling module. The power side waveform shows the effect of any resistance in the power side, including fuses, splices, relay contacts, and harness connections. Like the current ramp and the ground side drop, power side drop builds slowly as current flow increases.


In the example, Channel 2 was set to 200 mV/division using AC coupling. This setting shows you the change in voltage instead of the absolute voltage, allowing you to use small voltage settings. Using DC coupling, you* need about 2 Volts per division to see the trace, but that high setting would hide this 450 mV drop in supply voltage. Also like ground voltage drop, there is no firm specification. A few hundred mV is common, but the best way to know for sure is to compare to similar solenoids or published waveforms.


This screen was captured with the ATS Escope.



Supporting our community

Banner Diagnostic Network Banner Assurance iATN We are a Proud Friend of the NACAT Education Foundation ASE AESwave Ascca AESwave KivaAESwave