This circuit is an RCD Trip time tester without using Arduino or any other microcontroller.
You can order this PCB from here:
https://www.pcbway.com/project/shareproject/RCD_Trip_time_tester_without_using_microcontroller_.html
Parts list:
IC NE555
IC 40110 (3pcs)
Bush button switch (2pcs)
ON-OFF switch
Optocoupler PC817
Transistor 2N2222
7-Segment display common cathode single digit (3pcs)
Bridge diode BD107
Capacitor 100uF
Capacitor 100nF
Capacitor 10nF
Battery holder for coin cell battery
3V Coin cell battery CR2025 or CR2032 (2pcs)
Resistor 33K
Resistor 43K
Resistor 6.8K (2pcs)
Resistor 2K (21pcs)
Resistor 10K
Resistor 20K
Resistor 100K
Resistor 15K 2W
Resistor 7.5K 2W
Resistor 2.2K 2W
Resistor 1.5K 2W
IC Socket for 16 pin IC (3pcs)
IC Socket for 8 pin IC
Circuit:
You can download this circuit as PDF File with higher resolution from here:
https://drive.google.com/file/d/1-he9uydkw9ZIwsy9gbSuVbXgopcGTjfK/view?usp=sharing
You can order this PCB from PCBWay.com:
https://www.pcbway.com/project/shareproject/RCD_Trip_time_tester_without_using_microcontroller_.html
3D Printer files:
Part 1: https://www.tinkercad.com/things/feGAOmqfx8r-rcd-trip-time-tester-part-1
Part 2: https://www.tinkercad.com/things/10PYiPVujfl-rcd-trip-time-tester-part-2
Video:
I explained this circuit in following video
