Understand the fundamentals
Three quantities answer three questions
Voltage is the electrical “push” between two points. Its formal name is potential difference, and it is measured in volts (V). Voltage is what drives current around a complete path. Current is how much electric charge flows past a point each second. It is measured in amperes, or amps (A). Resistance is how strongly a part opposes current. It is measured in ohms (Ω). These are three different things, even when they appear together on one label.
A voltage rating does not tell you how much current is flowing right now. A miner can be energized, meaning electrical power is present, without doing any useful computing work. Also, a value in the miner’s software may be only an estimate. Or it may be measured at one point inside the miner, not at the facility supply.
See how it works
Use a simple circuit to learn the relationship
Ohm’s law links the three quantities for a simple resistor: voltage equals current multiplied by resistance. In symbols, V = I × R, where V stands for voltage, I for current and R for resistance. You can also write it as I = V ÷ R: current equals voltage divided by resistance. In a made-up 12 V circuit with a 6 ohm resistor, the current is 12 ÷ 6 = 2 A. This example teaches the relationship. It does not show how a real mining PSU draws power.
A miner’s power supply is not a simple resistor. It contains control circuits and fast-switching parts, so it does not act like one fixed resistance in every condition. Use simple calculations to help you read equipment information. Never use them as a reason to ignore the manufacturer’s ratings.
Visual explanation
Ohm’s law on a simple resistor
- Given
- 12 V across a 6 Ω resistor.
- Current
- I = V ÷ R = 12 ÷ 6 = 2 A.
- Power in the resistor
- P = V × I = 12 × 2 = 24 W.
This is a made-up DC circuit for practicing the math. It is not a build instruction, and it does not model a real switching PSU. No live measurements are needed.
Connect it to the field
Keep calculation and measurement separate
Working out a value from numbers you are given is a desk exercise. Measuring real electrical equipment is different. It adds hazards and needs suitable instruments, approved methods and qualified personnel. This lesson never asks you to put a meter on a live miner.
When you write down a value, say where it came from and include its units. For example: “dashboard input estimate,” “nameplate rated current” or “measurement supplied by the electrical team.” Then others can compare values without mixing up a maximum rating and a real operating reading.
Terms used in this lesson
- Voltage · V
- The electrical push between two points (potential difference), measured in volts.
- Current · A
- How much electric charge flows past a point each second, measured in amps.
- Resistance · Ω
- How strongly something opposes current, measured in ohms. Extra resistance in a poor connection can make that spot heat up.
Optional references & further reading
Use current manufacturer instructions for the exact equipment and your site’s approved procedures. Course levels do not grant task authorization.