DC Power Supply 9vDC 500mA (PS905USA) Unregulated
- voltage: 9V DC
- current: 500mA max.
- input: 115Vac / 60Hz
- thermal cutoff
- short-circuit protection
- DC plug: 2.5mm center x 5.5mm outside diameter
- positive inside
- cord: 6 feet
Important: When testing a non-regulated power supply, the output can fluctuate depending on the incoming voltage and the current amount the load draws. Unregulated power supplies have a design that delivers the expected output at a given current, but this does not always reflect the actual voltage output.
An unregulated power supply does not have the drastic increases and decreases in flow as it would have without a capacitor. The capacitor’s job of preventing severe swings in voltage helps, but this device does not create a perfectly clean output due to changes in both current load and voltage input.
Power equals the current times the voltage. If either the current or the voltage drop, the other variable increases to maintain steady power. While the energy from an unregulated power supply stays constant, the voltage output can drop or rise unexpectedly with a shift in the load current or the input voltage. Understanding how both input and output can affect the output is essential for deciding whether unregulated power supplies will suit your needs.
Note: The slight changes in voltage output do not matter for some applications. For these
applications, using an unregulated power supply can be an inexpensive option. However, if you use
a non-regulated power supply with electronics that require a consistent voltage, you could cause damage to the electronics or reduce its effectiveness. For such applications, you should use a regulated power supply.