Technical specifications of DC power supply
The technical indicators of DC power supply are divided into two types: one is characteristic indicators, including allowable input voltage, output voltage, output current, and output voltage regulation range, etc; Another type is quality indicators, which are used to measure the stability of the output DC voltage, including voltage stabilization coefficient (or voltage regulation rate), output resistance (or current regulation rate), ripple voltage (surrounding and random drift), and temperature coefficient.
(1) Ripple voltage: The AC voltage component superimposed on the output voltage. Observing its peak to peak value with an oscilloscope is generally in the millivolt range. An AC millivolt meter can also be used to measure its effective value, but since the ripple is not a sine wave, there is a certain error. Generally, the ripple voltage Vp-p of a DC power supply is ≤ 10mV.
(2) Voltage stabilization coefficient: Under the condition of constant load current and ambient temperature, the relative change of input voltage causes the relative change of output voltage, that is:
(3) Voltage regulation rate: The relative change in output voltage when the input voltage changes by ± 10%. The voltage regulation coefficient and voltage regulation rate both indicate the impact of input voltage changes on the output voltage, so only one of them needs to be tested.
(4) Output resistance and current regulation: The output resistance is the same as the output resistance of the amplifier, and its value is the absolute value of the ratio of the output voltage change to the output current change when the input voltage remains unchanged. Current regulation: The relative change in output voltage generated when the output current changes from 0 to the maximum value. The output resistance and current regulation rate both indicate the impact of load current changes on the output voltage, so only one of them needs to be tested.
