72-8350 TENMA, 72-8350 Datasheet - Page 4

• Manufacturer Part Number: 72-8350
• Description: POWER SUPPLY, BENCH, 20V
• Manufacturer: TENMA

Specifications of 72-8350

• Power Supply Output Type: Variable
• No. Of Outputs: 1
• Output Voltage: 20V
• Output Current: 5A
• Input Voltage: 90V AC To 130V AC
• Length: 250mm
• Width: 70mm
• Height: 150mm
• Weight: 4.4lb
• Approval Bodies: CE, EN
• Output Type: Variable

Basic Mode of Operation
This power supply is designed to operate as either a constant voltage or constant current source. Automatic crossover to either mode of
operation occurs when the load condition changes. The power supply functions as a constant voltage source (CV) as long as the load
current is less than the preset current limit value. When load current is equal to or greater than the preset current limit, the power supply will
automatically cross over to constant current (CC) mode. The voltage will drop, (CC) will show on the LCD display panel and the power
supply will operate as a constant current source. When the load current drops below the preset current limit, the supply will return to
constant voltage (CV) mode.
Operation
Presetting a Current Limit Value (CC)
In many cases, it becomes necessary to preset the current limit prior to having the load connected to the supply. To accomplish this, the
following steps should be followed.
Protection
To provide protection to the power supply and the connected load, the supply incorporates over voltage (OVP) thermal protection.
Traditional power supplies often provide over current protection, however that benefit already exists by sheer design of a current limiting
supply.
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Make certain the AC power cord is connected to a proper power source.
Make certain that no load is connected to the supply.
Switch on master ON/OFF POWER switch (1) on the rear panel, the LCD display backlight should illuminate.
The (CV) icon should be shown on the display and the OUTPUT (6) should default to OFF.
If current limiting is not required, turn the CURR (5) control fully clockwise.
If current limiting is required, see the steps in the following section “Presetting a Current Limit Value”.
Press the OUTPUT (6) button to activate the power supply output.
Set your desired output voltage, and then press OUTPUT (6) again to deactivate the output.
Observing correct polarity, connect to your load to the power supply.
Press the OUTPUT (6) button to activate the power supply output.
Check the power supply display to verify that the (CV) icon is displayed. If (CC) is displayed, your current limit value is too low,
the load requires more current than the supply is capable, or there is a fault in the connected device.
With no load connected to the supply, switch on the power.
Press the OUTPUT (6) button to the ON position to activate the supply output.
Adjust the VOLT (4) control to approximately 3VDC output.
Press the OUTPUT (6) button again to deactivate the supply output.
Turn the CURR (5) control fully counterclockwise.
Short OUTPUT terminals (7) and (9) together
Press the OUTPUT (6) button to the ON position to activate the supply output.
Adjust the CURR (5) control clockwise until the desired current limit is displayed.
Press the OUTPUT (6) button again to deactivate the supply output and remove the short between terminals (7) and (9).
The supply is now set for this current limit throughout its voltage range.
Over Voltage Protection ( OVP )
In the event that the output voltage control circuit mal-functions, the maximum output voltage will not exceed 30% of the adjusted
voltage value at the time of the operation.
Over Temperature Protection
If the temperature inside the supply exceeds a pre–determined value, the output voltage and current of the supply will decrease to
zero to prevent damage to the supply. When the temperature inside supply returns to approximately 65°C (150°F), the power
supply will automatically return to operation.