Re: star to earth gnd
They functioned for musiclistening, with lid of the case, but would have been too hot to use without fans when cased up.
tamasic1 said:I remember reading several different sources that said to be sure you use a 10ohm resistor between star and earth gounds if you were going to connect them together. Am I right on this?
Mayday, did you find those first heatsinks a little inadequate?
They functioned for musiclistening, with lid of the case, but would have been too hot to use without fans when cased up.
Re: star to earth gnd
I have not used a resistor between stargnd and earthgnd, didn't know you should.
tamasic1 said:I remember reading several different sources that said to be sure you use a 10ohm resistor between star and earth gounds if you were going to connect them together. Am I right on this?
Mayday, did you find those first heatsinks a little inadequate?
I have not used a resistor between stargnd and earthgnd, didn't know you should.
Hi Mayday,
the resistor between safety earth and audio ground is an optional item. It is not compulsory.
The resistor value can be set to near zero ohms (>=1sqmm copper wire) or in the range 2r7 to 22r. But if the resistor value alone would cause a high voltage across it when fault current flows then ANOTHER component MUST be placed in parallel to keep the voltage on the audio ground side at a safe level. The extra component should be able to survive kA of fault current until the mains fuse blows and the arc extinguishes.
the resistor between safety earth and audio ground is an optional item. It is not compulsory.
The resistor value can be set to near zero ohms (>=1sqmm copper wire) or in the range 2r7 to 22r. But if the resistor value alone would cause a high voltage across it when fault current flows then ANOTHER component MUST be placed in parallel to keep the voltage on the audio ground side at a safe level. The extra component should be able to survive kA of fault current until the mains fuse blows and the arc extinguishes.
Hi,ianpengelly said:
the 100uF is surprisingly large. It is more usual to be in the range 10nF to 100nF, to ensure it conducts HF.
I am surprised that attenuating at source was not completely successful, but maybe it needed just a bit more (I had not thought of this as an interference suppressor, but it obviously does not do nothing). I wonder if this is an indication that there might be somthing wrong with the fridge motor?
I couldn't find anything as low as 10 - 100nF when I was browsing Maplins, I may well replace it at a later date if I have any problems in the next house.
I am please that I have now proved my theory from the other thread, which is that using 1 transformer and 2 rectifier boards (from the Brian GT dual mono kits) results in an interaction that manifests itself as hum and it is solved by either using 1 rectifier board for both channels or using 2 transformers, one per channel.
As for the pop, I would expect it to be down to the switch in the fridge rather than the motor, just because of the type of noise it is, i.e. very short duration pop. Of course you could be right and there maybe a earthing problem with the motor.
I am please that I have now proved my theory from the other thread, which is that using 1 transformer and 2 rectifier boards (from the Brian GT dual mono kits) results in an interaction that manifests itself as hum and it is solved by either using 1 rectifier board for both channels or using 2 transformers, one per channel.
As for the pop, I would expect it to be down to the switch in the fridge rather than the motor, just because of the type of noise it is, i.e. very short duration pop. Of course you could be right and there maybe a earthing problem with the motor.
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