1. This common DC protection board uses an optocoupler. Since the optocoupler has input and output isolation, 2. Electrical signal transmission has the characteristics of unidirectionality, so it has good electrical insulation and anti-interference ability. 3. Since the input end of the optocoupler belongs to the low-resistance type of current type operation, it has strong common mode suppression capability. 4. The and are separated, and the will not be affected! Note: 1. The protection board uses 1.6 thick 1A copper surface, double-sided tin plating process, the input voltage is DC12V-16V or AC 12-16V. 2. Turn on the (red) indicator light, the work indicator light is normal, the relay is closed, if the impact protection board automatically adjusts the suction time (waiting for the current to pass through the relay)! 3. The supply can be the as the amplifier. Each of the three channels of the audio source is . It is suitable for non-common ground and BTL circuit amplifiers. 4. The terminal block is 7.62 pitch, and the 1/2W metal film exceeds the standard. The internal resistance is reduced for high current design! 5. The ​relay ​as the core component is not afraid of contact sparking and oxidation, and lossless transmission of sound! roduct description: With delay and DC protection (default 1.8V control, DC sensitivity can be adjusted) Protection board parameters: Channel design: three channels Can withstand : within 300W x 3 Material:PC+Metal colour:As shown Package Contents: 1 * Speaker Protection Board Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.