QJE Manuals & User Guides

QJE is a specialized brand of power supply equipment manufactured by Jiuyuan Electronics. Renowned for its reliability and precision, the brand offers a wide range of DC power supplies, including programmable laboratory models, linear power supplies, and high-efficiency switching mode units. QJE products are widely used in educational institutions, electronic repair facilities, and by amateur radio enthusiasts (HAM radio) due to specific features like noise offset controls designed to minimize interference with communication devices.

The product lineup includes popular models such as the QJ3005P programmable lab supply and the PS30SW series tailored for communications. These units typically feature digital LED displays, adjustable voltage and current settings, and robust protection mechanisms against overcurrent and short circuits. With a focus on providing stable and clean power, QJE continues to be a trusted name for powering sensitive electronic equipment.

• How do I use the Noise Offset function on my QJE power supply?

  Many QJE switching power supplies, such as the PS30SWI, feature a Noise Offset knob. This control adjusts the switching frequency of the power supply to move any generated switching noise away from the frequency you are currently using on your connected radio communication equipment.

• How do I switch between Constant Voltage (C.V.) and Constant Current (C.C.) modes?

  Cross-over between modes is automatic. You set your desired voltage and current limits. If the connected load draws less current than your limit, the unit operates in Constant Voltage mode. If the load attempts to draw more current than the limit, the unit automatically switches to Constant Current mode to protect the device.

• Where can I find the fuse on my QJE power supply?

  The fuse is typically located on the rear panel near the AC input socket. If replacement is necessary, ensure you unplug the unit, wedge the fuse holder out, and replace the fuse with one of the exact same type and rating (e.g., F5A/250V) as specified in your user manual.

• Can I control QJE programmable power supplies with a computer?

  Yes, models like the QJ3005P and QJ3003GIII feature USB interfaces specifically for remote control via PC software. This allows for setting voltage/current parameters and monitoring waveforms on a computer.

• What should I do if the OCP indicator lights up?

  If the Over Current Protection (OCP) indicator flashes, it means the output current has exceeded the set limit and the output has been cut off. Disconnect the load, check for short circuits, and press the OCP key to recover normal operation.