Time Mode Operation; Checking And Changing Operating Parameters - BIO RAD 200/2.0 Instruction Manual

Turn the Power Supply Off
There are three different ways to turn the power supply off.
1. Press VOLTS. The red indicator light should be on. Press LOWER until the LED display
reads OFF. Using this method preserves the volt-hour reading until the voltage is reset,
but resets all of the other functions to their default values.
2. An alternative method to turn the power supply off is to press VOLTS. The red indicator
light should be on. Press RAISE and LOWER simultaneously. The LED will display
OFF. If the load has already been disconnected, the LED will display OFF for 1 second,
then the decreasing voltage will be shown until it reaches 30 volts. Below 30 volts, OFF
will be displayed. Using this method preserves the volt-hour reading as long as RAISE is
not held down long enough to reset the voltage.
3. The third method to turn the power supply off is to turn the power switch off. This auto-
matically resets all functions to their default values, including the volt-hour integration
data. Note: The power supply left on with no load attached consumes approximately 12
watts of power (equivalent to a night light).

2.2 Time Mode Operation

General Application: The Model 200/2.0 power supply can operate at constant voltage or
constant current for a set time. The power supply automatically shuts off and the alarm sounds
when the set time has elapsed.
1. Set the current limit as in Section 2.1.
2. Set the timer.
• Press TIMER. The red indicator light above the button should be on, and the LED display
should read 00.0.
• Press and hold RAISE until the LED display reads the correct time. The timer displays
tenths of hours. It may be necessary to use both RAISE and LOWER to reach the desired
setting.
3. Set the voltage as in Section 2.1.
4. The timer begins to count as soon as the voltage is above zero, and will count down from
the set time to zero. When the timer reaches zero, the alarm will sound, and the power
supply will shut off. The LED display will read OFF.
5. To turn the alarm off, press any one of the function buttons.
6. Turn the power switch off, if desired.

2.3 Checking and Changing Operating Parameters

General Application: The current, voltage, current limit, time remaining (if the timer has
been set), resistance load, power output, and volt-hours can be checked during a run to monitor
the progress of the experiment or to troubleshout. The current limit, operating voltage, and set
time may be changed at any time during a run.
1. Press AMPS to view the operating current. The red indicator light above the button should
be on, and the operating current will be shown on the LED display.
2. Press VOLTS to view the operating voltage. The red indicator light above the button
should be on, and the operating voltage will be registered on the LED display. To alter the
voltage, follow the procedure in Section 2.1.
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