DC regulated power supply main performance acceptance, measurement method
I Precautions:
1) Measurements shall be made in such a way that the quantitative value of the cumulative effect of all other influence quantities is less than 1/10 of the specified quantitative value of the effect to be measured.
2) The load is a variable influence quantity, and when the load is continuously adjustable, it shall be carried out at the two points of the minimum and maximum values (when the minimum value is zero, it is specified to be carried out at 10% of the maximum value).
3) A four-terminal line should be used to separate the current terminal from the measurement terminal to minimise measurement error.
4) When the power supply provides measurement terminals, it should be carried out on the measurement terminals, and the test head of the digital voltmeter should be inserted into the centre hole of the terminal block to the end.
5) When measuring the current stabilised power supply, the sampling resistor RM should be used so that the voltage drop on it is proportional to the current and should be less than 1/10 of the error limit of the measured effect, and the error caused by it should be considered in the error analysis, and at the same time, the sampling resistor R M should be used in four-terminal line so that the current terminal and the measurement terminal are separated to reduce the measurement error.
6) When the voltage or current stabilised output is continuously adjustable, it shall be carried out at the two points of minimum and maximum values (when the minimum value is zero, it is specified to be carried out at 10% of the maximum value).
II Test Methods
Measurement of Load Effect and Periodic and Random Offset.
1 ) The measurement of load effect is the measurement of the amount of change in the stabilised output of voltage or current due to a change in load only.
2 ) Periodic and random offset measurements are measurements of the irregular fluctuation portion (formerly known as ripple and noise) of the stable output of voltage or current. The measurement frequency range is: 10Hz~10MHz, and a single ground point must be used for the measurement to avoid measurement errors.
3) Measurements should be made within the interval of 1.5 to 11.5 seconds after completion of load regulation.
4 ) Measurement should be made when the source voltage is set at 198V, 220V and 242V respectively.
