AMETEK DCS-E 1KW Series - Manual (Page 56)

Theory of Operation Sorensen DCS Series 1kW and 1.2kW Supplies
3-10 M362500-01 Rev H
3.2.1 Voltmeter
U2 is a 3 1/2 digit analog to digital converter which converts the analog input from the A2 board
voltage control circuit to a digital display on seven segment displays DS5-DS8 (maximum
display is 1999). The 6.2V reference from pin 5 of connector J1 is divided down by resistors
R16 and R17 and potentiometer R18 to provide the reference for the converter. The analog
input from the voltage control circuit (via pin 6 of connector J1) is filtered by resistor R9 and
capacitor C14 before it is input to pin 31 of the converter. Capacitor C12 and resistor R7 set
the conversion frequency to approximately 3 times per second. Resistors R8, R11 and R12 are
used to select the appropriate decimal point position depending on the model of the power
supply.
3.2.2 Current Meter
The current meter circuit operates in the same manner as the voltage meter circuit with U1
performing the conversion for display on DS1-DS4. Capacitors C4 and C6 provide additional
filtering on the meter analog input. Resistors R2, R5 and R6 are used to select the appropriate
decimal point.