Author: Steve Morrison, BS - Electrical Engineering Technology, MBA

Steve Morrison Credentials: - Bachelor's Degree in Electrical Engineering Technology - Purdue University - Master's Degree BA - University of Florida - 8 Years of Television/Radio Repair - Morrison TV & Electronics, Inc - Gainesville, FL - 15 years of cumulative Appliance Service - 2 Years as hardware Engineer performing circuit board, firmware, middleware, and user interface development - Leapfrog Smart Products - 9 Years as Senior Technical Engineer performing hardware (circuit board prototypes) proof of concept development, software/smart card development, logical access system POC middleware development. and technical writing with primary client being the Department of Defense - Founder & Creator for BBCircuits YouTube Channel - Founder & Creator for "The Tech Circuit" YouTube Channel - Admin/Editor for "The Tech Circuit" website - Creator/Admin of "The Tech Circuit" Facebook Group

The War of the Currents – DC will Replace AC

AC power in the home has been around since near the end of the 19th century. Almost all of world’s power distribution infrastructure is based on it. In fact, there was a time when practicality no other technology would work. It had superior transmission efficiency and was compatible with emerging industrial-age motor technology. However, based […]

What is Impedance?

What is Impedance What’s the difference between Impedance and Resistance? We hear the term “impedance” all the time. What is it though? Why not just use the term resistance? That’s because in AC circuits, resistance, which is the opposition to current flow, is called impedance. But unlike resistance, impedance can also include the effects of […]

Electricity – Talk the Talk

Articulating Electrical Behavior is Important As a technician, it is crucial to have a fundamental understanding of how electricity works. It’s also important to articulate that information in a functionally-accurate and understandable way. By effectively describing the electrical scenarios you come across, you can impress your customers, more readily seek assistance from and provide support […]

Refrigerator Inlet Valve Diodes – How they Work

What are Inlet Valve Diodes? For some inlet valve solenoids, diodes are used to logically control which valves are energized for a given function. A common configuration is where a safety (or main) valve is energized when either a refrigerator dispenser or icemaker solenoid is energized. In this way, one safety valve can be used […]

Resistance is not Futile

How Resistance Damages High-Current Connections Blocks, Connectors, and Cords We’ve all seen it. Burned up terminal blocks. Heat stressed quick-connects. Blackened and melted dryer or range cord plug prongs. What causes this though? Yeah, we all know its because of a loose connection. But why does it happen? It’s really Ohm’s law and the power […]

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, […]