Hi Experts,
I am working on a Rockford Fosgate Punch 801s. I am in the testing phase, and it seems to be working as expected. I know these get hot when driving the minimum load (4 ohms bridges to load both channels equally).
Hot, is a relative term so I am looking for some numbers. I measured the heat sink at over 185 Fahrenheit (85 degree Celsius) and it still did not go into thermal protection. That is hot enough to burn you if you touch it.
Is this considered normal for these amps?
I am working on a Rockford Fosgate Punch 801s. I am in the testing phase, and it seems to be working as expected. I know these get hot when driving the minimum load (4 ohms bridges to load both channels equally).
Hot, is a relative term so I am looking for some numbers. I measured the heat sink at over 185 Fahrenheit (85 degree Celsius) and it still did not go into thermal protection. That is hot enough to burn you if you touch it.
Is this considered normal for these amps?
Hi Perry, no it does not get hot at idle.
It seems to be properly biased with 0.5 to 0.8 over the resistors for each MOSFET
I just don’t want to return an amp with a non-functional protection circuit, if that is the case.
It seems to be properly biased with 0.5 to 0.8 over the resistors for each MOSFET
I just don’t want to return an amp with a non-functional protection circuit, if that is the case.
Looking at the input to the comparator for thermal protection, was it on the verge of switching on?
At the time the amp was to hot to handle comfortably (without oven mitts). I will test the amp again and monitor the input to the compactor in order to determine if it was close to switching on.
Some of the resistors around the protection circuit for the temperature control was out of tolerance. Especially the two resistors, forming the resistor divider with the NTC, R39 and R40. The original values was 1.21K. I ended up settling on using 1.33K metal film resistors with low temperature coefficients +- 50ppm/degC and this worked.
It shut the amp down at about 70 degree Celsius and restarted it when it got to about 67 degree Celsius.
Thought I would close the loop on this discussion.
It shut the amp down at about 70 degree Celsius and restarted it when it got to about 67 degree Celsius.
Thought I would close the loop on this discussion.
I think Rockford uses 80C as the protection point. 70 is OK.
It's normal for all amps to be far too hot to touch (for more than a fraction of a second) at thermal shutdown.
It's normal for all amps to be far too hot to touch (for more than a fraction of a second) at thermal shutdown.
Yes, I have observed that the other Rockford amps I have worked on cycle at around 80-85C.
This one was still around 400mV from switching when looking at the input to the comparator for thermal protection at 85C and I thought this was too far from switching.
Appreciate the input Perry!!
This one was still around 400mV from switching when looking at the input to the comparator for thermal protection at 85C and I thought this was too far from switching.
Appreciate the input Perry!!