The scenario
A 24V DC supply feeds a fused control circuit where a switch energizes a relay coil; the relay contact then switches a hydraulic solenoid valve, while flyback diodes across both coils suppress inductive voltage spikes.
What is in this drawing
Read the decisions behind it.
01
Use a normally-open relay contact to isolate the low-power control switch from the high-current solenoid valve.
02
Place flyback diodes reverse-biased across the relay coil and the solenoid valve to protect against back EMF.
03
Fuse the 24V supply upstream of both the control and load branches.
When a PLC output or manual switch must control a 24V DC hydraulic directional valve without exposing the control circuit to inductive kickback.
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