00:00Main's voltage will kill low-voltage microcontrollers instantly.
00:04Opticouplers provide galvanic isolation to keep logic boards safe.
00:085 Cheap Options Tested Under $2
00:11First up, TLP291-4 Series Quad Channel Pack in SOP16 Package.
00:17Cost is $18 for 4 pieces.
00:21Gives 4 independent isolation channels per chip.
00:24Saves board space on multi-channel AC detection circuits.
00:27Solid 4.5 rating with near 5,000 sold.
00:32Best for compact multi-relay driver setups on tight budget.
00:36Second option, TLP280-4 and TLP283-4 5-pack.
00:41Price is $40.
00:44Ships with 4.8 rating across almost 5,000 orders.
00:48High current transfer ratio options like GB grade ensure clean logic switching from low-LED drive currents.
00:55Reliable choice when driving MCU inputs directly from rectified main sense lines.
01:00Third pick, 10-piece mixed lot covering TLP281, TLP290, and TLP291 variants.
01:08Costs just $0.85 total.
01:10Gives maximum channel count per penny at under $0.09 per chip.
01:144.8 rating confirms high yield.
01:18Ideal for stocking workbench parts bins without spending money.
01:22Fourth choice, another 10-piece multi-variant lot at $1.39.
01:27Highest-rated batch at 4.9 stars with over 2,000 orders shipped.
01:32Sellers test these batches more consistently, meaning near-zero debt on arrival silicon.
01:37Spend extra $0.50 here if you hate troubleshooting bad clone optos on freshly soldered boards.
01:43Final pick, 5-piece single-channel pack covering TLP181, TLP185, and TLP291 in tiniest OP4 footprints.
01:52Drops price to just $0.56.
01:55Small package keeps creepage distances easy to route on single-channel mains zero-cross detectors.
02:01Rating is 4.7.
02:04By this one board area matters more than channel count.
02:08All component links in description below.
02:11Like video, subscribe to channel for more bench tests.
02:15Drop questions in comments.
