For operators who have just been introduced to the use of stable power supply, there is a lack of substantive understanding of the basic concept of dc power supply. Such as constant voltage, constant current, ohm's law, the main structure of the power supply.The analysis can be divided into three aspects:
1. There is a voltage without a current, or a current without a voltage.
In either case, the power supply is working properly, and the operator should check that his load is in good contact, that the load is short-circuited or open, that the load is compliant, etc.
In extreme terms, if the dc supply has a voltage output (constant voltage) and the load line is cut, the natural output current is zero.Similarly, if the power supply has a current output (constant current state), and the load is short-circuited, the natural output voltage is equal to zero.
2. When the voltage is adjusted, the no-load voltage cannot be adjusted.
Some operators like to turn the "current regulator" potentiometer left to the end, so that the power supply no-load voltage is not up. This shows his lack of substantive understanding of "current regulation". Because a power source consumes a little current even when it's empty, and if you turn the "current regulator" off to zero, you won't release even a little current, and of course the no-load voltage won't rise.So "current regulation" generally do not set to zero, (to the right around a quarter of the circle will not happen).
3. Dc power supply has voltage output, also have current output, and then adjust the voltage, the voltage can not be adjusted up.Or the power supply has voltage output and current output, and then want to increase the current, the current is not large.
This is because the operator is not clear about the concept of "constant pressure" and "constant current".If the "constant voltage" lamp is on, it indicates that the dc power supply is working at constant voltage.The output current is determined by the load, not by the operator, (it can be said that the current is in a passive position), if you turn the right "current adjustment" knob, the current will not increase.But then go to the right "voltage regulation" knob, the output voltage will increase, the output current will also increase.Voltage is the main, current is from).
Similarly, if the "constant current" lamp is on, it means that the power supply is working in the state of constant current. At this time, the output voltage is not "adjusted", but determined by the load.Only by adjusting the "current adjustment" knob can the output current change and the output voltage change accordingly.