Apex BA2000 protection circuit

[shehantha]

hi I found that Proline 3000 also same as ba2000. but i don't know how the protection circuit works without any power supply.

pls see the attached pdf schematic. protection circuit stars only from sp out and then goes to GND.

Can any expert explain this or is there any mistake on the schematic ?

also can someone design the input board pcb layout ?

 

[sajti]

hi I found that Proline 3000 also same as ba2000. but i don't know how the protection circuit works without any power supply.

pls see the attached pdf schematic. protection circuit stars only from sp out and then goes to GND.

Can any expert explain this or is there any mistake on the schematic ?

also can someone design the input board pcb layout ?

The protection use the +24V supply, just the connection is missing from the schematic.

Sajti

 

[shehantha]

thanks sajti for the reply. according to prolone 3000 user manual they have mention that this amp has short circuit protection also, but when see the protection circuit schematic i cannot think that it has short circuit protection.

just normal dc protection and fan speed and thermal sensor.

if theres short circuit prot. then there should be a connection from output transistor emiter to the prot. circuit. but i cannot find it.

or is there any other method they use for short circuit protection here ?

 

[andrewlebon]

Shehantha you are right if you are diying the amp all protections can be made

 

[sajti]

if theres short circuit prot. then there should be a connection from output transistor emiter to the prot. circuit. but i cannot find it.

or is there any other method they use for short circuit protection here ?

T155, T156 acting as V/I limiter. They reduce the output current in case of overload, or short circuit. There is no relation to other protection.

Sajti

 

[shehantha]

many thanks for the reply sajti. Now I understood it. one more thing, I am going to make the pcb layout for the input section. but there are some unclear points for me,

1. after the first op amp , next to 4.7uf theres a PTC resistor. but they have not mention the value

2. and also i never seen 4148 diodes use in input with supply. is schematic correct ?

If anyone owns the proline 3000 or 3600 pls kindly tell me the value of that ptc ( which goes to 2nd op amp's negative signal point.
( is this ptc should mount on the main heat sink )

thanks

 

[rhythmsandy]

any successful builds of the ba2000?