The amplifier features delay, dc protection, and temperature monitoring across the speaker protection circuits. Since the application of short circuit protection is not flexible, most speakers are not in the protection circuit. You can use the appropriate one according to your amp, which will include various short circuit protection circuits.
For the first circuit transistor amp circuits, it detects current through the equalization resistors of the power transistors and triggers the DC protection circuit. You can add to your current protection circuit or you can add another transistor and control the relay directly.
Note: I do not recommend doing the experiments by short-circuiting the direct amp output, adjust according to the current drawn on the load, then measure the current drawn by your amp and establish a connection accordingly or max. run at load and set the protection circuit to work, then increase the trimpot value a little and try again at max power. This time, the protection circuit will not work, so the current drawn will be active when the short circuit is high. When performing tests, take into account sudden peaks, especially in bass.
Speaker short circuit protection circuit diagram and pcb drawing
The E + section will be connected to the equalization resistor of the transistor (2sc5200 or IRFP240) from the positive supply stage.
The circuit diagram is not very clear for the connection below, see the sample diagram about the amp, dc protection connection.
The second speaker short circuit protection circuit can be used in many more flexible amp circuits, but the resistance of the resistor must be connected to the loudspeaker line with a resistance of 0.2 or 0.5 ohm, and the power of the resistor will vary according to the amp.
Simple version (untested)
Article Source: 320volt.com