Hi,
I'm just seeking some clarification with the wiring of my SMPS with the protective earth and star grounding.
Question 1) I know that the earth from the IEC socket should connect to the chassis with a short wire, but should the Earth connection on my SMPS (LRS-100-36) go direct to the eic earth, or both meet at the same chassis point?
Question 2) I have 2 grounds on my PCB (pwr & aud) which come back to a star ground. Is it ok to bring them back go the chassis point with PE, or should they go to a separate point on the chassis?
Im using 17awg wiring for the 240/10A ac.
Is the attached correct or does it need a change? (ps i have covid and took about 4 hrs to write this. sorry if its a bit jumbled!)
I'm just seeking some clarification with the wiring of my SMPS with the protective earth and star grounding.
Question 1) I know that the earth from the IEC socket should connect to the chassis with a short wire, but should the Earth connection on my SMPS (LRS-100-36) go direct to the eic earth, or both meet at the same chassis point?
Question 2) I have 2 grounds on my PCB (pwr & aud) which come back to a star ground. Is it ok to bring them back go the chassis point with PE, or should they go to a separate point on the chassis?
Im using 17awg wiring for the 240/10A ac.
Is the attached correct or does it need a change? (ps i have covid and took about 4 hrs to write this. sorry if its a bit jumbled!)
The drawing is correct with regards to the PE (use correct names please) connection of the SMPS. What is wrong are the connections of PWR and AUD GND to PE. They should be connected to Audio GND not PE.
I stopped being the master in searching but you could look up that PSU and find out if its output - is already connected to the PE pin of that PSU... then you can decide on a strategy.
PE = primary/mains side of things. Audio GND is secondary side of PSU. BTW the standby switch is not the best idea as switching DC causes pitting of contacts. Many amplifiers like recent class D amplifiers have special standby pins.
I stopped being the master in searching but you could look up that PSU and find out if its output - is already connected to the PE pin of that PSU... then you can decide on a strategy.
PE = primary/mains side of things. Audio GND is secondary side of PSU. BTW the standby switch is not the best idea as switching DC causes pitting of contacts. Many amplifiers like recent class D amplifiers have special standby pins.
Thanks for the feedback. I've found the block diagram and it looks as if FG (PE) and V- (DC GND) are connected.
PWR_GND and AUD_GND are both on the dc side and should be coming back to the same point. How would you go about this? Sorry, I've lost myself!
PWR_GND and AUD_GND are both on the dc side and should be coming back to the same point. How would you go about this? Sorry, I've lost myself!
Well I don't see the connection. Only with a cap. Please measure resistance (in de-energized state so no mains power!) from the Meanwells "PE" to its "-V". Don't worry about that too much at this moment. PE is for safety and should be connected to the casing. That is mandatory and the minimum for safety. That connection is there so the casing is safe to touch.
PWR_GND and AUD_GND should go to the -V side of the "PSU filter" as current flows to/from there. I don't know the filter in detail so directly to the - of the Meanwell also is a possibility as a second choice. That is all for now to connect and test. IF there is no hard connection between the Meanwells "-V" and its own "PE" connection then we can go on from there. It would involve a small modification then but more about that later.
And what about the standby switch? Any comment on that? What is the purpose? Normally one only uses a mains switch and a delayed relay for the speakers. The way the mains switch and its L and N connections are drawn it won't do much 🙂 In your situation you will have the power on/off plops both with operating the mains switch and with the standby switch. Double trouble. If the hole for the standby switch is already cut then using the switch to operate a good quality speaker relay near the speaker outputs is a possibility.
PWR_GND and AUD_GND should go to the -V side of the "PSU filter" as current flows to/from there. I don't know the filter in detail so directly to the - of the Meanwell also is a possibility as a second choice. That is all for now to connect and test. IF there is no hard connection between the Meanwells "-V" and its own "PE" connection then we can go on from there. It would involve a small modification then but more about that later.
And what about the standby switch? Any comment on that? What is the purpose? Normally one only uses a mains switch and a delayed relay for the speakers. The way the mains switch and its L and N connections are drawn it won't do much 🙂 In your situation you will have the power on/off plops both with operating the mains switch and with the standby switch. Double trouble. If the hole for the standby switch is already cut then using the switch to operate a good quality speaker relay near the speaker outputs is a possibility.
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The secondary switch is just a throw back in my mind to all my guitar amps and doesn't serve a honest function so i'll drop that. I've got a relay on the amp board to stop pops on a 555 timer.
As for the chassis, theres a few annoyances with it on my end anyway so i might just redo it as i have spare sheet metal here.
I'll reply regrding the power supply tomorrow as i need new batteries for the multimeter and im in isolation currently 🙂 getting a care package tomorrow.