UPC1237 Power Amplifier Speaker Protection Circuit Board Boot Delay DC Protection Support BTL Power Amplifier Board|Instrument Parts & Accessories| - AliExpress
Upc1237 Speaker Protection Board (compatible With The Btl Protection) - Instrument Parts & Accessories - AliExpress
Single Ac/dc12v 10a Upc1237 Dual Channel Speaker Protection Circuit Board With Lm7812 Regulator Features - Home Theater Amplifiers - AliExpress
2 Channel Upc1237 Speaker Protection Circuit Board Ac 12v-16v Protective Module With Time Delay Relay For Amplifier - Instrument Parts & Accessories - AliExpress
DIY uPC1237 Speaker protection version 2 schematic with Komitart LAY6 format PCB.