motorboating shielding power supply capacitors

#Motorboating shielding power supply capacitors how to#

However, under high frequency, its isolation is very unsatisfactory. The switching power supply works at a high frequency, which will change the characteristics of the low-frequency components, resulting in noise.Ī transformer in a switching power supply is used for isolation and voltage transformation. What we can do to reduce that is to make rational design or layout, and try to control the way of noise. They charge and discharge all of a sudden under the state of switching on and off, especially the parasitic capacitance of the transformer, the capacitance between the semiconductor device and the radiator as well as the capacitance between the wire and the frame. Parasitic capacitance inside power supplyĪnother source of noise in switching power supply is the internal parasitic capacitance. Because of its high frequency, it radiates directly to space in the form of electromagnetic energy, or transmits along the input/output wires in the form of an interfering current.Ģ.

#Motorboating shielding power supply capacitors how to#

So how to reduce the noise of SMPS? First of all, we need know where the noise comes from, and then we can eliminate it accordingly.ĭuring the turn on and turn off of switch and rectifier tubes, the radio frequency energy generated by the change of large current is the main source of noise.

But it has its own disadvantage of producing noises, which not only affect the normal operation of the circuit, but also interfere with the neighboring electronic equipment. The next time it motorboats is there anyway i can troubleshoot while the amp is on and making the noise? I've tried to include as much relevant info as possible so sorry if it's long winded Any advice is welcome.Switching power supply (SMPS) is widely used due to its compact size, light weight and high efficiency. A couple of small pieces if velcro on the lip of the chassis solved most of the rattle). The only other thing that has been done lately is the chassis was pulled to solve a vibration rattle issue(The chassis was vibrating against the screen mesh on the top. From what I've read it's most likely a cathode bypass cap that has drifted out of spec right? Can tubes cause a motorboating sound( I promise it really is a motorbating sound ? Since it's an intermittent issue tube swapping to see if it's gone will be pretty difficult.

The amps electolytic, and filter caps were replaced when I bought it. I've been doing a lot of preamp tube swapping lately but the tubes in it now are the ones that have been solid for awhile. I changed my phase inverter about a month ago from a Mullard 4024 to a Blackburn Mullard ecc81. If it is a tube then it's causing a motorboating issue. My questions are this, can tubes cause motorboating? I've had the amp for about 4-5 years now and have become quite familiar with what a microphonic tubes sounds like. When he heard it he said it was definitely motorboating. He's built his own 5f4 clone and does most of his own amp repairs. The other guitarist in my band is pretty knowledgeable with amps. I hit the standby and again it was gone when I flipped it back on. Tonight about a week and a half later I was at band practice and when we finished a tune it started doing it again. I hit the standby switch turned it back on and it was gone. About a week ago I was playing at home and all the sudden I hear a loud putting sound that started in one pitch and then wound down to a lower pitch and kept put putting in the same pitch.