Introduction to DC Regulated Power Supplies
A DC regulated power supply is an electronic device that provides a stable DC power supply to a load. Most DC regulated power supplies are powered by AC power, and the DC output voltage of the regulator remains stable even when the voltage of the AC power supply or the load resistance changes. As electronic devices develop towards higher precision, higher stability, and higher reliability, higher demands are placed on the power supply for these devices.
Basic functions of DC regulated power supply
1. The output voltage value can be set arbitrarily below the additional output voltage value and operate normally.
2. The stable current value of the output current can be set arbitrarily below the additional output current value and operate normally.
3. The voltage and current regulation status of the DC regulated power supply can be automatically changed and there are corresponding status indicators.
4. The output voltage and current values must be accurately displayed and identified.
5. For DC regulated power supplies with precise output voltage and current values, multi-turn potentiometers and voltage/current fine-tuning potentiometers are generally required, or direct digital input may be necessary.
6. A complete protection circuit is required. The DC regulated power supply should not be damaged when a short circuit or abnormal operating condition occurs at the output terminal, and should be able to resume normal operation immediately after the abnormal condition is eliminated.
DC regulated power supply operation process
Step 1: Power Connection. Connect the regulated power supply to the mains power.
Step 2: Turn on the power. With no load connected, press the main power switch (power), and then turn on the DC output switch (output) to allow the power supply to operate normally (some simple adjustable voltage regulators only have a main power switch and no separate DC output switch). At this moment, the current operating voltage and output current will be displayed on the power supply's digital indicator.
Step 3: Set the output voltage. Adjust the voltage setting knob until the digital voltmeter displays the target voltage, completing the voltage setting. For power supplies with adjustable current limiting, there are two adjustment systems that regulate voltage and current separately. It's important to distinguish between them during adjustment. Generally, potentiometers for voltage adjustment are marked "VOLTAGE," while potentiometers for current adjustment are marked "CURRENT." Many entry-level products use low-cost coarse/fine adjustment dual knobs. When encountering dual adjustment knobs, first turn the fine adjustment knob to the center position, then set the approximate voltage using the coarse adjustment knob, and finally use the fine adjustment knob for precise correction.
Step 4: Set the current. Press and hold the "Limit" button on the power supply panel. The ammeter will display the current value. Adjust the current knob until the current reaches the desired level. Generally, the current limit can be set to 120% of the commonly used maximum current. Some power supplies do not have a dedicated current limit adjustment button; in this case, the user needs to short-circuit the output terminal according to the instruction manual, and then set the current limit level based on the short-circuit current and the current limit knob. Simple adjustable voltage regulators do not have a current setting function or a corresponding knob.
Step 5: Set Overvoltage Protection (OVP). Overvoltage setting refers to further limiting the upper limit voltage within the power supply's adjustable voltage range to prevent excessive voltage output in case of accidental operation. Generally, the overvoltage can be set to 120% of the highest normal operating voltage. Overvoltage setting requires a flathead screwdriver to adjust the recessed potentiometer on the control panel; this is also a design feature to prevent accidental activation. When setting the OVP voltage, first adjust the power supply's operating voltage to the target overvoltage point, then gradually adjust the OVP potentiometer until the power supply protection activates precisely. At this point, the OVP setting is complete. Then, turn off the power supply, lower the operating voltage, and it will operate normally. Refer to Step 3 above for setting the operating voltage. Different power supply settings require different OVP methods.
Step 6: Communication interface parameter settings and remote control operation settings. For local control applications (panel operation), remote control operation must be disabled. The communication interface must be set according to communication requirements; no settings are required for local applications.
Precautions when using a DC regulated power supply
1. Based on the required voltage, first adjust the "coarse adjustment" knob, then gradually adjust the "fine adjustment" knob, ensuring correct coordination. For example, if a 12V output voltage is required, the "coarse adjustment" knob should be set to the 15V range, and then the "fine adjustment" knob should be adjusted to 12V. The "coarse adjustment" knob should not be set to the 10V range. Otherwise, the maximum output voltage will not reach 12V.
2. After adjusting to the required voltage, connect the load.
3. During use, if it is necessary to change to the "coarse adjustment" setting, the load should be disconnected first, and the load should be connected again after the output voltage is adjusted to the required value.
4. During operation, if a short circuit or overload causes a power outage, the load should be disconnected first, and then the "Restore" button should be pressed. Alternatively, the power can be turned on again, and the voltage will return to normal operation. The load can be reconnected after the fault has been cleared.
5. When multiple power supplies with different additional currents are connected in series, the output current is the additional value of the one with the smallest additional current.
6. Each power supply has a meter that indicates the output current or output voltage of that circuit under different A/V conditions. It is generally set to voltage indication mode.
7. Each channel has two output terminals, red and black. The red terminal indicates "+", and the black terminal indicates "-". The black terminal in the center of the panel with the "ground" symbol indicates that this terminal is connected to the chassis and has no electrical connection with any output channel; it is used only as a safety line. People often mistakenly assume that the "ground" symbol indicates grounding and that "+" and "-" indicate positive and negative power outputs to power the dual-power op-amp.
8. Two voltage sources can be used in series. Parallel connection is absolutely prohibited. A power supply is a measuring instrument; therefore, the output terminals must not be short-circuited for extended periods.
