Calibration and raw ADC values

59 17. Calibration and raw ADC values Note: Some familiarity with calibration methods is required. Use at least 6 ½ digit known-good multimeters, and allow a warm-up of at least 1 hour before attempting calibration. The RD uses separate ADC settings for the output regulation (Output V/I) and the display (Back V/I). Note that the RD will not show negative values, so if you are below 0, it will still show 0. As a result, it is better to calibrate the zero values using small non-zero values. 17.1. How to do the Calibration on the device The calibration can be done from the “screwdriver” menu. The calibration process is similar to the process from the PC software. You could use the Raw ADC Values to derive the correct settings if you want, but it will be easier to interactively use V-Set and I-Set directly from the calibration menu, and go from there. The password is the same as on the PC software: 168168. How to use: ● Go to the “screwdriver” menu. ● Enter the password. Start with an arrow down or up and use a mix of rotary knob and left-right arrow keys to enter the password. Afterwards press ENTER. The number keys do not work for this step. ● If the password is correct, the calibration menu will be displayed. There are all the necessary parameters (including Back V-BAT and BackInput which are unavailable in software). ● After selecting a parameter, the corresponding formula is displayed at the bottom of the display, according to which the firmware calculates the values. ● The changes are applied immediately (in RAM), so you can see the result. ● Click on (SHIFT)+(Dot) sets the selected parameter to the factory setting. ● Select the desired action and press ENTER (!!! The cursor must be on the button !!!) NOP No Operation (does nothing, exit the menu without resetting the password) CANCEL Cancels all settings (loads current values from EEPROM) STORE Stores current changes to EEPROM RESTORE Restores factory calibrations (from a backup copy. Similar to holding the button (1) at power on). ● Clicking on the encoder resets the password and closes the menu Note: Calibrations are not saved/restored by themselves. All changes that are not saved with STORE

• ENTER, will remain only until reboot.

60 At the bottom of this menu, there is a text line with CW/CCW counters, these are for testing the Encoder. The counters are reset with UP/DOWN buttons. 17.2. How to do the Calibration from the PC software From Riden Power Supply Software, Calibration tab, password 168168. To restore factory calibration (it is unique for each device): Pressing "1" while Powering ON. You might want to understand the Raw ADC Values for this process. {ToDo - Add more detail here, add screen shots … }{A} 17.3. Raw ADC values The raw ADC values, selectable from the ‘Status info’ setting, can be used to adjust, or confirm, the calibration settings of the RD60xx. Vout = ADC(V) * backVoltageScale / 100000 - backVoltageZero

61 Iout = ADC(I) * backCurrentScale / 100000 - backCurrentZero For example, let's calibrate the "backVoltage" values:

1. Find ADC(V)0, the ADC ‘Zero’ value: ● Ensure the output is OFF and the output capacitors are discharged. ○ Observe the value of ADC(V) for a while. ● Take the highest value and add 1. (In this example, the highest value observed was: 143.) ○ ADC(V)0 = 143 + 1 = 144
2. Find ADC(V)x, the ADC reading of a known (calibrated) value. (For this example let it be 50V) ● Set output to 50.00V and turn ON. ● Using the “ENCODER” Knob, adjust output voltage to be as close to 50V, as measured using a calibrated multimeter. ○ Observe the value of ADC(V) for a while. ● Take the most stable value (usually a middle one). (In this example, ADC(V)x = 29109)
3. Calculate calibration constants: Scale = (Calibrated Value * 100,000) / (ADC(V)x - ADC(V)0) (In this example, ‘Calibrated Value’ = 50V, in tens of mV = 5000) = (5000 * 100,000) / (29109 - 144) = 17262 Zero = (ADC(V)0 * Scale) / 100,000 = (144 * 17262) / 100,000 = 24 Notes: When calculating with the ADC values for current: ● RD6006 the ‘Calibrated Value’ is in: mA (ie. 1А = 1000) ● RD601x the ‘Calibrated Value’ is in: tens of mA (ie. 1A = 100)