Delton 303D Technical manual

303D
DC Regulated Voltage and Current Power
Supply Operation Instruction
1. General Description
The DC power supply is high accuracy linear power supply. It is single channel constant voltage and current DC
voltage stabilizers with the features of low ripple noise, high stability, and high accuracy. It have the capability of
series connected and parallel connected to enhance the loading capacity of the power supply.
This is a stable voltage and current automatic transfer type of power supply with regulated uninterruptible output
voltage. It has characteristic of high precision and stable. The output voltage can be adjusted from zero up to more in
the range of rated voltage. Furthermore, the limited current protection also can be freely chosen. The stable output
current can be adjusted in the range of below table.
This constant voltage and current DC voltage stabilizers is suitable for scientific research, laboratory, teaching,
electronic product lines and communication industry as well as necessary equipments.
2. Basic parameter specifications and Panel features
2-1 Panel feature of power supply
(1) Current indication
(2) Voltage indication
(3) Current fine tuning
(4) Current coarse tuning
(5) Voltage fine tuning
(6) Voltage coarse tuning
(7) Constant current indicator
(8) Constant voltage indicator
(9) Power switch
(10) Power output “+” terminal
(11) Power output “-” terminal
(12) Power ground “GND” terminal
2-2 Nominal Operation Conditions
●Input voltage: AC 220V ± 10%, 50Hz ± 2Hz
●Output voltage: DC 0～30V
●Output current: DC 0～3A
●LED display accuracy:
Voltage: ± (1.0% + 1digit), Current: ± (2.0% + 2digits)
●Protection: Current limited protection and short-circuit protection
●Operation conditions: Temperature: 0℃~40℃, Relative Humidity: ≤90%
●Storage conditions: Temperature: -20℃~60℃, Relative Humidity: ≤80%
●Dimension: 275(L)×132(W)×157(H) mm
●Working time: 8 hours continuously (temperature 20 ± 5℃)

2-3 Constant Voltage Status
●Voltage Stability: ≤0.01%+3mV
●Load Stability: ≤0.02%+3mV
●Ripple and Noise: ≤1mV rms (Effective Value)
2-4 Constant Current Status
●Current Stability: ≤0.2%+6mA
●Load Stability: ≤0.2%+6mA
●Ripple and Noise: ≤10mA rms (Effective Value)
3. Direction For Use
3-1 Precautions
1) AC input: AC input should be 220V ±10%, 50Hz ± 2Hz.
2) Isolation: There is a temperature switch in the power supply, when inside temperature is upper than 45℃, the fan
will revolve automatically for heat abstraction. Do not use it in conditions of temperature above 40℃, the heat
abstraction fan is on the back of the instrument, there should be enough room for heat abstraction.
3-2 Operating Method
1) Before turn on the instrument, “adjustable knob” (3) & (4) should be adjusted to maximum clockwise. After turning
on, respectively adjust knob (5) and (6) to the required voltage. As a usual practice, first to adjust knob (6) to the
approximate voltage, then adjust knob (5) to the precisely required voltage, meanwhile the light (8) is on while the
light (7) is off.
2) Loading connection
The instrument is on, (1) is output current, and (2) is the output voltage. If the current shown in the display window is
over the rated current and the light (7) is on, it means the output voltage is overload or short-circuit. At this time,
adjust the loading to restore the instrument to normal working.
3) Using this instrument as stable current supply, after turning on the power, first should adjust the (5) & (6) to the
maximum clockwise, meanwhile adjust (3) & (4) to the minimum counter-clockwise. Then connect the loading, adjust
knob (3) & (4) clockwise to the required current, at this time, the light (7) is on while the light (8) is off.
4) Using this instrument as stable power supply, usually adjust the knob (3) & (4) to the maximum, in this time, can
choose limited current protection point freely.
Way: turn on the power, connect the proper changeable loading and regulate the loading resistance to let output
current equal to current limited protection point, then adjust the knob (3) & (4) close to light (7) on, so the current
limited protection is well set up.
5) When used in places with high ripple factor, either “+” or “-” connector should be connected to GND connector
tightly, so the ripple voltage would decrease.
6) Attention: Do not start the power supply with load, nor the power supply and the load would get damaged.
7) The LED meter is 3 digits, More accurate output result should be got by more precise instrument outer set.
4. Maintain
4-1 Replacing the fuse
If the fuse breaks, the power supply will stop operating, in this occasion, the cause of the break must be found out,
and after correction, use a same fuse（2A/250V，Φ5×20mm）to replace the broken one, the fuse box should not be
open unless the problem happens.
4-2 Maintain
Once the power supply inside is burnt out, it must be repaired by professionals or sent to the dealer to send back to
the factory for repair. Do not repair it separately to ensure safety.