Kicker ZX1500.1 protects when driven hard

[peeby]

While steadily increasing drive input it works well until it is drawing approx 50 amps on the bench ps and then it goes into protect (prior to output clip).

Although I do not believe I have maxxed out my bench supply, could amp be doing this due to limitations of the supply? Usually an amp just starts to output clip when it maxes out my supply, but not go into protect.

Am about to trace out the overcurrent circuit as I have no drawings.

Any help would be great.

[RussellKinder]

Hi peeby,

Once upon a time I designed amps for Kicker, but long before the ZX1500.1 came out. (in other words, I don't have a schematic.) This could be due to supply limitations. Peak current can be well in excess of average current. Perhaps you could try putting a hefty car battery in parallel with your 50 A supply.

This shutdown would be due not to overcurrent protection in the amplifier, but the undervoltage lockout protection at the battery input. Do you have an oscilloscope that you can monitor the battery voltage at the amplifier? If it drops below 10V, that may be a problem, and if it drops below 8V, that's a shutdown event.

[RussellKinder]

Also, the folks at Kicker are pretty friendly. You can probably get some tech support.

[PapaZBill]

What is the size of your bench supply. If 50 amp this won't be enough. A car battery in parallel would work as Russell suggested.

If you still have issues post pics of board. I have schematics and can walk you through any repairs.

Hi Russell btw still fixing the occasional ZR! Truly a legacy line of Amps!

[RussellKinder]

See, I told you they were friendly.

[peeby]

Thank guys. Will get back on it tomorrow.

[peeby]

Put a 12V truck battery in parallel with my bench supply.

Question - so when I first paralleled the battery and the PS the PS was charging the battery, so it saw the battery as a load. Could the PS be seeing the battery and the amp as a load?

Amp is still opening the relay before it clips.

Voltage at amp is well above 12v when amp relay opens.

[Perry Babin]

The battery's charge was lower than the PS voltage. In that situation, the battery was a slight load.

You need to put a cutoff switch and a fuse in series with the battery for safety.

[peeby]

So with it being a slight load, did it help increase or decrease the current available to the amp?

[Perry Babin]

It depends on the supply voltage. If the supply voltage is very low (ie 10.5v), the battery won't do much. If the supply voltage is 13v or greater, a healthy battery will help greatly.

The files in the following folder show how much current a healthy, fully charged battery can deliver and the voltage that it's dragged down to at that current. Above 12.5v, the battery will contribute little or nothing to the supply voltage.

You'll need to view full size to see the lines clearly.

Index of /temp/battery test