Timeline for Start-up current of amp triggers circuit breaker
Current License: CC BY-SA 4.0
9 events
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| Apr 24, 2020 at 4:37 | comment | added | xeeka | A brown out seems to be not related to this case of an anti-inrush resistor which is in series with the amp's normal "big transformer" power supply for a very short time < 1 second. The problem in the question - switching a device with an external switch - is the weak point of this kind of "make-before-make" switch. Although not a student, it would be very interesting to learn about a series resistor that "will make the problem worse". | |
| Apr 23, 2020 at 22:11 | comment | added | Ed Beal | It is called brown out this damages electronic circuits in big cities every summer but you know it all so be it. If it was so easy to build a special switch industry would be doing that but there is 2 ways transformers and VFD’s. Are you a high school electronics student? | |
| Apr 23, 2020 at 20:01 | comment | added | xeeka | @EdBeal "If it is a switching power supply the issue is having to charge the capacitors and WILL make the problem worse" How can a series resistor make the (in rush current) problem worse with either a normal or a switched power supply? Do you have any example/reference? This would be very interesting to learn, since it is extrememly hard to understand. "You can think you have a solution "- The special switch is rather part of the analysis, since it was speculated this type of switch could have been used by the manufacturer. But it is useless if the amp is switched by an external switch. | |
| Apr 23, 2020 at 19:44 | comment | added | Ed Beal | If it is a switching power supply the issue is having to charge the capacitors and WILL make the problem worse, as I said without the type of supply throwing anything at it is called shot gunning. You can think you have a solution but there is not enough information available. Inrush can be either capacitive or inductive doing the wrong thing causes a brown out condition and can damage the circuits. | |
| Apr 23, 2020 at 19:30 | comment | added | xeeka | @EdBeal "The resistance would have to be a large wattage" - this is why it is a special switch with built-in resistor and with a special forced mimic/timing to limit the time for the series circuit to a fraction of a second. "You don’t want to make your power factor worse as that may be part of your inrush problem" The inductance is the problem. The series resistor can only improve the power factor - how could you make the PF worse with a series resistor? It was stated that the amp has a "big transformer". | |
| Apr 23, 2020 at 19:10 | comment | added | Ed Beal | Putting a resistance inline can cause additional issues depending on the type of supply. The resistance would have to be a large wattage to be able to handle the load, depending on the type of power supply an inductance can make the problem worse. I am an electrician with an electronics degree. You don’t want to make your power factor worse as that may be part of your inrush problem. If we had the make and model of the amp we could identify the type of supply. | |
| Apr 23, 2020 at 18:15 | comment | added | xeeka | An inductance will decrease the inrush current. But the transformer of the amp most likely is not optimized for small remanence. When the amp is switched off, there may be a huge remanence left in its core. Depending on the polarity and the phase angle pairing of the next switch on moment, the inductance could be only very small resp. the core could be saturated yielding a very high inrush current, which is still increased by the large empty capacitances on the secondary side. Maybe the amp has a special power switch which bridges an anti-inrush resistor during the switch operation. | |
| Apr 23, 2020 at 15:39 | comment | added | Darki | Well simple inrush current limiter often simply use a series resistor which gets disconnects after a few ms. (I don't think about something advanced as an inverter here) I guessed this could work, because in combination with the transformers inductance I would expect it to slow down the inrush current? Splitting and basically adding new wires is actually planed for later, when we also add a rcd to our house. About the wiring, actually no one knows how it was done. The owner once did it himself with a friend... we also have annoying ground-loops. | |
| Apr 23, 2020 at 13:46 | history | answered | Ed Beal | CC BY-SA 4.0 |