It's possible that this design was created with a big reserve in mind, so using heat-sinks & fuse might be overkill for the purpose.
I saw similar device (SMD PCB), where output connected to IRF8313 Power Mosfet without heat-sinks. It max total current is 5A though.
So I should use MOSFET with lower Thermal resistance junction-case RthJC value, smaller the value it is better the heat radiation.
Would be these a good substitute: Infineon [link...
Theoretically, max power is 2A x 12V = 24W per driver circuit: so I still have some power reserve?
Possibly, I can use copper area around DPAK Mosfet for heat dissipation?
For THT cdesign, would be fine to use resistors with 1/4W power rating for all elements or it need be calculated?
If use SMD design, what is common SMD resistor size (Code) that can be used here? (Imperial/ Mectric)
Yes, internal jumper, or DIP switch. DIP switch perhaps better, I need SPDT DIP Switch (ON-ON, without center position). Searched on Digikey, but still didn't find good accurate one. The line-in input is Terminal block, not 1/8" plug socket, and Mic is on board.
Could anyone suggest switch/input selector for mounting on PCB (through-hole)? Device have two inputs, Mic and Lin-in input. Capsule Micro Electret Mic Ø10mm in mounted on PCB, Mic is default input mode. When I need switch to Line-in input, I just put jumper. Or maybe some other small handy switch.
For through-hole mounting trimpots, Digikey offer 120 models for given criteria. What type is better suitable for application? does Tolerance % matter?
Normal means "for indoor use". -10C to +60C / 14F to 140F Not in aerospace industry. :)
@BrianG For myself, yes. You are absolutely right, assembling SMD PCB professionally at home is very difficult, and also requires a very sharp vision, and solid hand-soldering skills. I didn't plan to...
