Hi,
I wrote to Hypex to determine the maximum capacitance that can be applied to the output of the Hypex SMPS400A400 power supply to reduce bus pumping. Their response was that :
"It is unsupported to apply extra capacitance on the output of the supply. The surge current could damage the supply."
Has anyone any experience of using reservoir capacitors on their SMPS units - (63volt units) ?
Of course there will be local reservoir capacitance as per the class D amplifier, so the blanket statement that it is not supported seems overly cautious.
Thanks and regards for any feedback on this.
Regards,
Shadders.
I wrote to Hypex to determine the maximum capacitance that can be applied to the output of the Hypex SMPS400A400 power supply to reduce bus pumping. Their response was that :
"It is unsupported to apply extra capacitance on the output of the supply. The surge current could damage the supply."
Has anyone any experience of using reservoir capacitors on their SMPS units - (63volt units) ?
Of course there will be local reservoir capacitance as per the class D amplifier, so the blanket statement that it is not supported seems overly cautious.
Thanks and regards for any feedback on this.
Regards,
Shadders.
Hi,
From :
Avoid Overvoltage Stresses by Minimizing | Maxim Integrated
A strange phenomenon can occur with Class D audio amplifiers that have single-ended output loads: the power-supply voltage increases as power is delivered to the load. The phenomenon is known as power-supply "pumping,"
Regards,
Shadders.
From :
Avoid Overvoltage Stresses by Minimizing | Maxim Integrated
A strange phenomenon can occur with Class D audio amplifiers that have single-ended output loads: the power-supply voltage increases as power is delivered to the load. The phenomenon is known as power-supply "pumping,"
Regards,
Shadders.
Hi,
I will not be using the system at such levels where it will regularly exceed 400watts. Should there be a transient which does not exceed 400watts, yet can still cause "some" bus pumping, then my preference is to counter this with reservoir capacitance. Something is better than nothing.
Regards,
Shadders.
I will not be using the system at such levels where it will regularly exceed 400watts. Should there be a transient which does not exceed 400watts, yet can still cause "some" bus pumping, then my preference is to counter this with reservoir capacitance. Something is better than nothing.
Regards,
Shadders.
These supplies are designed to power single ended class D amps. (Like all the Hypex amplifiers). Because the supply was designed this way, they designed it to tolerate supply pumping. And they did so by using mosfets that can sink current, rather than a rectifier like most supplies use. So adding caps will only worsen the supply quality, and potentially damage it like the Hypex engineer told you.
