The circuit of this project adopts an approximate four wire connection method. In addition to commonly used, you also need to understand these electronic manufacturing services. Here is a circuit design for the production of double-layer circuit boards, which will be detailed in the following four circuit diagrams.

A circuit board is the soul of a circuit and needs to connect every node of the circuit. On this basis, the wires and each node are treated as electronic components, connecting all nodes and components of the circuit, thereby completing the circuit connection and simplifying the design process of electronic components.
● Power connection wire, used for connecting two separate power sources or connecting input and output components. The signal levels between the input and output components are mutually off, when the AC input stage is used.
Relay output, used for output isolation and switching relays, helps to quickly switch load current.
● Load switch, allowing it to be connected to the power supply and load. Therefore, when connecting the outputs of multiple relays to the main power supply, the output voltage is set to be the most dense and kept at a distance from the coil or contact of the relay.
RU4NK-ZD - R7 103 ± 5% R7 100kHz ± 1% RU4NK-ZD - R7 100kHz ± 1% R9 100kHz ± 1% R10 100kHz ± 1% RU4NK-VE - R7 100kHz ± 1% R9 200kHz ± 1% R10 10nF (5nF) ± 1% R11 R9 500kHz ± 1% R15 R66 630 ± 1% ± 3% R23 100kHz ± 1% ± 3% R90 2V (3 Ω) ± 250mV ± 2% ± 10% R19 500kHz ± 50% R23 ± 2% R22 500kHz ± 50% R23 ± 20% ± 100% R25 ± 20% ± 10% R23 ± 10% ± 200% R25 ± 10% R23 ± 10% ± 200% R23 ± 10% R23 ± 10% R23 ± 10% R23 ± 400% ± 200% R23 ± 10% ± 300% ± 500% R23 ± 420% ± 1000% R23 ± 005% ± 10% R23 ± 1000% ± 100% ± 204% ± 500% ± 20% ± 50% ± 100% ± 85% ± 80% ± 85% ± 50% ± 100% ± 85% ± 50% ± 20% ± 15% ± 30% ± 25% ± 24% ± 20% ± 35% ± 50% ± 60% 125% ± 50% ± 3% ± 55% ± -40% ± 100% ± 70% ± 125% ± 80% ± 110% ± -55% ± 85% ± 150% ± 100% ± 15% ± 25%