EESchema Schematic File Version 4 LIBS:esp-current-transformer-cache EELAYER 26 0 EELAYER END $Descr USLetter 11000 8500 encoding utf-8 Sheet 1 1 Title "Wemos D1 mini CT interface" Date "2019-11-17" Rev "D1" Comp "Plugh Industries" Comment1 "" Comment2 "" Comment3 "" Comment4 "" $EndDescr $Comp L wemos_mini:WeMos_mini U1 U 1 1 5DD0C81B P 5800 3650 F 0 "U1" H 5800 4393 60 0000 C CNN F 1 "WeMos_mini" H 5800 4287 60 0000 C CNN F 2 "" H 6350 2950 60 0000 C CNN F 3 "http://www.wemos.cc/Products/d1_mini.html" H 5800 4181 60 0001 C CNN 1 5800 3650 1 0 0 -1 $EndComp $Comp L Transformer:CST2_Split T1 U 2 1 5DD0CD5D P 7950 4200 F 0 "T1" V 7904 4303 50 0000 L CNN F 1 "CST2_Split" V 7995 4303 50 0000 L CNN F 2 "Transformer_SMD:Transformer_Coilcraft_CST2" H 7950 4200 50 0001 C CNN F 3 "https://www.coilcraft.com/pdfs/cst.pdf" H 7950 4200 50 0001 C CNN 2 7950 4200 0 1 1 0 $EndComp $Comp L Device:R_US R1 U 1 1 5DD0CE60 P 7000 4350 F 0 "R1" H 6932 4304 50 0000 R CNN F 1 "280k" H 6932 4395 50 0000 R CNN F 2 "" V 7040 4340 50 0001 C CNN F 3 "~" H 7000 4350 50 0001 C CNN 1 7000 4350 -1 0 0 1 $EndComp $Comp L Device:R_US R2 U 1 1 5DD0CEF6 P 7000 4650 F 0 "R2" H 7068 4696 50 0000 L CNN F 1 "280k" H 7068 4605 50 0000 L CNN F 2 "" V 7040 4640 50 0001 C CNN F 3 "~" H 7000 4650 50 0001 C CNN 1 7000 4650 1 0 0 -1 $EndComp $Comp L Device:R_US R3 U 1 1 5DD0CF78 P 7550 4200 F 0 "R3" H 7618 4246 50 0000 L CNN F 1 "R_US" H 7618 4155 50 0000 L CNN F 2 "" V 7590 4190 50 0001 C CNN F 3 "~" H 7550 4200 50 0001 C CNN 1 7550 4200 1 0 0 -1 $EndComp Wire Wire Line 5300 3400 5150 3400 Wire Wire Line 7950 3900 7550 3900 Wire Wire Line 7550 3900 7550 4050 Wire Wire Line 7550 4350 7550 4500 Wire Wire Line 7550 4500 7950 4500 $Comp L Device:CP1 C1 U 1 1 5DD0D824 P 7550 4650 F 0 "C1" V 7298 4650 50 0000 C CNN F 1 "CP1" V 7389 4650 50 0000 C CNN F 2 "" H 7550 4650 50 0001 C CNN F 3 "~" H 7550 4650 50 0001 C CNN 1 7550 4650 1 0 0 -1 $EndComp Wire Wire Line 6300 3300 7000 3300 Wire Wire Line 7550 3900 6550 3900 Connection ~ 7550 3900 Connection ~ 7550 4500 Connection ~ 7000 4500 Wire Wire Line 7000 4800 6550 4800 Wire Wire Line 5150 3400 5150 4800 Wire Wire Line 7000 4800 7550 4800 Connection ~ 7000 4800 Wire Wire Line 7000 4500 7550 4500 Wire Wire Line 7000 4200 7000 3300 $Comp L Device:D_Zener_ALT ZD1 U 1 1 5DD0EF0C P 6550 4350 F 0 "ZD1" V 6504 4429 50 0000 L CNN F 1 "3.3V" V 6595 4429 50 0000 L CNN F 2 "" H 6550 4350 50 0001 C CNN F 3 "~" H 6550 4350 50 0001 C CNN 1 6550 4350 0 1 1 0 $EndComp Wire Wire Line 6550 4200 6550 3900 Connection ~ 6550 3900 Wire Wire Line 6550 3900 6300 3900 Wire Wire Line 6550 4500 6550 4800 Connection ~ 6550 4800 Wire Wire Line 6550 4800 5150 4800 $Comp L Jumper:SolderJumper_3_Open JP1 U 1 1 5DD0E3E4 P 3800 3100 F 0 "JP1" V 3754 3168 50 0000 L CNN F 1 "PS voltage selector" V 3845 3168 50 0000 L CNN F 2 "" H 3800 3100 50 0001 C CNN F 3 "~" H 3800 3100 50 0001 C CNN 1 3800 3100 0 1 1 0 $EndComp $Comp L vce03:VCE03 PS1 U 1 1 5DD0E493 P 3050 3200 F 0 "PS1" H 3050 3565 50 0000 C CNN F 1 "VCE03" H 3050 3474 50 0000 C CNN F 2 "" H 3050 3250 50 0001 C CNN F 3 "https://www.xppower.com/Portals/0/pdfs/SF_VCE03.pdf" H 3050 3250 50 0001 C CNN 1 3050 3200 1 0 0 -1 $EndComp Wire Wire Line 3800 3300 5300 3300 Wire Wire Line 6300 3300 6300 2750 Wire Wire Line 6300 2750 3800 2750 Wire Wire Line 3800 2750 3800 2900 Connection ~ 6300 3300 $Comp L power:AC #PWR? U 1 1 5DD0F51D P 2450 3100 F 0 "#PWR?" H 2450 3000 50 0001 C CNN F 1 "AC" V 2450 3329 50 0000 L CNN F 2 "" H 2450 3100 50 0001 C CNN F 3 "" H 2450 3100 50 0001 C CNN 1 2450 3100 0 -1 -1 0 $EndComp $Comp L power:Earth #PWR? U 1 1 5DD0F61B P 2450 3300 F 0 "#PWR?" H 2450 3050 50 0001 C CNN F 1 "Earth" H 2450 3150 50 0001 C CNN F 2 "" H 2450 3300 50 0001 C CNN F 3 "~" H 2450 3300 50 0001 C CNN 1 2450 3300 0 1 1 0 $EndComp Wire Wire Line 3650 3300 3650 3400 Wire Wire Line 3650 3400 5150 3400 Connection ~ 5150 3400 Text Notes 3600 3000 0 50 ~ 0 3.3V Text Notes 3650 3250 0 50 ~ 0 5V Wire Notes Line 1950 2500 3600 2500 Wire Notes Line 3600 2500 3600 3550 Wire Notes Line 3600 3550 1950 3550 Wire Notes Line 1950 3550 1950 2500 Text Notes 2050 2700 0 50 ~ 0 Optional, circuit may be USB powered\nVCE03US03, VCE03US05, or equivalent Text Notes 5200 5100 0 50 ~ 0 R1/R2 provide bias voltage for ADC input (since CT output will go negative).\nSchematic is for Vcc/2 because the D1 mini has another divider on board to\nmake the ADC's input range 0-3.3V (vs. 0-1V for the ESP chip directly). Text Notes 7600 3550 0 50 ~ 0 TODO: notes on burden resistor sizing,\npick some good defaults $EndSCHEMATC