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Electronics Testing Equipment
Updated September 20, 2025
Bench power supply
A bench power supply is an adjustable tool that provides stable DC power for testing electronic circuits. It allows precise control of voltage and current.
Category
Electronics Testing Equipment
Use Case
Powering and testing electronic circuits during development or repair
Key Features
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Adjustable Voltage And Current Output
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Digital Display For Precise Readings
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Multiple Output Channels For Flexibility
In Simple Terms
What It Is
A bench power supply is a tool that gives you control over electricity for testing electronic devices. Think of it as a smart, adjustable wall outlet. Instead of just providing a fixed amount of power like a regular charger, it lets you choose exactly how much voltage (the push behind the electricity) and current (the flow of electricity) you want to supply. It usually has dials or buttons to set these values and a digital screen to show you what’s happening in real time.
Why People Use It
People use bench power supplies because they offer a safe and precise way to test and power electronic projects. When you’re building or repairing something like a circuit board, you don’t want to risk damaging it by giving it too much power. With a bench power supply, you can start with low voltage and current and slowly increase them to see how the device behaves. It also helps you find problems—if a device isn’t working, you can check if it’s getting the right amount of power or if it’s drawing too much current, which might indicate a short circuit.
Everyday Examples
Imagine you’re building a small LED lamp. You could use a bench power supply to slowly increase the voltage until the LED lights up brightly without burning out. Or, if you have an old radio that won’t turn on, you could use the bench power supply to mimic batteries and see if the radio works when given the correct power. Hobbyists often use these supplies for testing homemade gadgets, while repair technicians rely on them to safely check everything from smartphones to game consoles without using their original chargers or batteries.
Technical Details
Definition
A bench power supply is a precision electronic instrument designed to provide stable, adjustable DC power to circuits and devices during development, testing, and repair. Unlike fixed power adapters, it allows an operator to manually set both the output voltage and the maximum output current, serving as a versatile and controlled power source for a workbench environment.
How It Works
The unit typically converts AC mains input to a regulated DC output. An internal transformer first steps down the AC voltage, which is then rectified and filtered to produce a rough DC voltage. This unregulated DC passes through a voltage regulator circuit, which uses feedback control to maintain a precise output voltage regardless of changes in load or input variations. The user-set voltage and current limits are achieved through potentiometers or digital controls that adjust reference voltages within this feedback loop. Many modern supplies incorporate digital microcontrollers for setting parameters, displaying readings, and implementing protection features.
Key Components
Transformer: Steps down the AC mains voltage to a safer, lower AC level.
Rectifier and Filter: Converts AC to pulsating DC and smooths it into a more stable, unregulated DC voltage.
Voltage Regulator: The core circuitry that provides precise, stable, and adjustable output voltage.
Control Interface: Knobs, buttons, or a digital keypad for setting voltage and current limits.
Display: Typically an LCD or LED screen showing set values and actual output voltage and current.
Binding Posts: Terminals (often banana jacks) for connecting output leads to the device under test.
Cooling Fan and Heat Sink: Manages heat generated by the regulator components during operation.
Rectifier and Filter: Converts AC to pulsating DC and smooths it into a more stable, unregulated DC voltage.
Voltage Regulator: The core circuitry that provides precise, stable, and adjustable output voltage.
Control Interface: Knobs, buttons, or a digital keypad for setting voltage and current limits.
Display: Typically an LCD or LED screen showing set values and actual output voltage and current.
Binding Posts: Terminals (often banana jacks) for connecting output leads to the device under test.
Cooling Fan and Heat Sink: Manages heat generated by the regulator components during operation.
Common Use Cases
Prototyping and debugging new electronic circuits by providing a known, clean power source.
Testing the operating limits and failure modes of components by deliberately varying voltage and current.
Powering and characterizing devices like motors, LEDs, or amplifiers under different supply conditions.
Charging batteries in a controlled manner by using the constant current (CC) mode.
Repairing electronic equipment by substituting for a faulty internal power supply.
Testing the operating limits and failure modes of components by deliberately varying voltage and current.
Powering and characterizing devices like motors, LEDs, or amplifiers under different supply conditions.
Charging batteries in a controlled manner by using the constant current (CC) mode.
Repairing electronic equipment by substituting for a faulty internal power supply.
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