Video Explanation of how Relay Coil Resistance Affects Boards

For decades, I have considered coil resistance when replacing relays. This video, which was published in December of 2019, describes in detail why coil resistance is important to relay circuits. Right at about 4:10 in the video, I start this discussion. This blog and associated video is intended for experienced or supervised technicians. Always take […]

Lab Results – 365 ohm RT334012 vs. 270 ohm OZ-SS-112LM1

Important Note Never attempt to repair circuit boards in appliances or HVAC systems unless you are directly supervised by a licensed professional engineer and doing so under approved ISO and UL processes. What Can Happen to a Relay Control Circuit if you Replace an RT334012 with an OZ-SS-112LM1 These results are based on a standard […]

Relay Substitution and Coil Resistance

Important Note on Board Repair Never attempt to repair circuit boards in appliances or HVAC systems unless you are directly supervised by a professional engineer and doing so under approved ISO and UL processes. What is an Electrically Equivalent Replacement Relay? Some Appliance and HVAC Technicians perform board-level repairs and often replace relays. Their replacement […]

Build a Microwave Diode Tester

Build a microwave diode tester that shows a green light for forward bias. It uses 18V to ensure enough voltage to forward bias the diode. This tester can also be used for biasing zener diodes and semiconductor junctions in general. In this article, a detailed description and instructions are provided, along with a parts list, […]

The Power of Perceived Value

How do you make most every customer a happy customer with almost no extra effort? How do you build instant trust from your customer? How do you get repeat-business, referrals, and positive reviews from almost every customer? How do you turn naturally suspicious, untrusting customers into the kind of customer you want? Steer their perceptions […]

Electrical Diagnostic Basics – Bare Minimum “Must-know” Concepts for Appliance and HVAC Technicians

Electricity for Appliance and HVAC Technicians. What do they Need to Know? Appliance and HVAC Technicians will inevitably encounter electrical problems that they must troubleshoot. In order to effectively diagnose these circuits, Technicians must understand some fundamental concepts. This blog describes five bare-minimum electrical rules that once understood, will help better position Technicians for the […]

Resistors, Capacitors, Inductors, Diodes, and Transistors – What is their purpose?

What Resistors, Capacitors, Inductors, Diodes, and Transistors do. If you work on anything electrical or electronic, you’ve seen these components. What are they used for though – and how do they work? This blog gives you the short answers. What does a resistor do? A resistor limits current flow. It is analogous to a bottleneck […]