The HY1803D is a reasonably priced power supply that will provide suitable power for many low-power electronics projects. From the manual, the specifications are:
Voltage Output: 0 V-18 V DC ± 1% in increments of centivolts (0.01 V)
Current Output: 0A - 3A ± 2% in increments of centiamps (0.01 A)
Operating Environment: -32 - 104 °F, relative humidity < 90%
Please note: this guide will use the term "Current knob" to refer to the "Coarse adjustment of current " and "Voltage knob" to refer to the "Coarse adjustment of output voltage " depicted in the second image.
Step 1: Plug It In
Plug in the power supply. It requires:
104-127 VAC at 60 Hz
207-253 VAC at 50 Hz
North America main power is 120 VAC, 60 Hz
Step 2: Constant Voltage Mode
To output a constant voltage, first turn the Current knob clockwise until it stops. Turn on the supply, and use the Voltage knob to the desired level. Attach the load to the output terminals. The red terminal is positive, and the black terminal is ground. NOTE: THE SUPPLY IS NOT PRESENTLY IN CURRENT LIMITED MODE. BE CAREFUL YOU DO NOT DAMAGE YOUR ELECTRONICS! THE SUPPLY CAN OUTPUT A MAXIMUM OF 3A.
Step 3: Constant Current Mode
To turn the supply into an adjustable current supply, FIRST ENSURE IT IS OFF. Turn the Voltage knob completely clockwise until it stops. This is the maximum voltage setting. Turn the current knob completely counter-clockwise until it stops. This is the minimum current setting.
Turn on the supply, and attach the load to the output terminals.The red terminal is positive, and the black terminal is ground. Slowly adjust the Current knob by turning it clockwise to the desired level.
Step 4: Enable the Current Limit
This mode is very useful for protecting delicate electronics such as ICs, PCBs, and the like.
FIRST MAKE SURE NO LOAD IS ATTACHED, and turn on the supply. Turn the Current knob counter-clockwise until it stops. This is the minimum current position. Turn the Voltage knob the the desired voltage output
Attach the load to the output terminals (red is positive, black is ground). SLOWLY turn the Current knob to the desired current limit.
NOTICE: In the event of a short circuit at the output, the current will limit at the value set by the Current knob. However, the unit should be turned off and the short circuit removed before continuing use.