Safe In-Wall AC to DC Transformers??
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More from the 'guru'
"There is no input fuse, that is the reason I recommend one and it has to be a real fuse that blows, not a fuse that will automatic recover. The only time it is supposed to blow is if the converter blows and then you want the mains permanently disconnected. Probably a 0.2A slow fuse will work."
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More from the 'guru'
"There is no input fuse, that is the reason I recommend one and it has to be a real fuse that blows, not a fuse that will automatic recover. The only time it is supposed to blow is if the converter blows and then you want the mains permanently disconnected. Probably a 0.2A slow fuse will work."
@rvendrame Thanks for the clarification.
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And a 250VAC fuse is fine to use on 120VAC (and in fact quite common).
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Ok, how does this look for parts?
70 degree (Celsius) fuses - http://www.ebay.com/itm/10pcs-Thermal-Cutoffs-SEFUSE-Microtemp-Thermal-TF-Cutoff-NEC-Fuses-73-C-240-C-/221560426284?var=&hash=item339607cf2c
.75A fuse - They are fast blow not slow like specified above. Does that matter?? http://www.ebay.com/itm/40Pcs-ELECTRIC-FUSE-FAST-BLOW-0-75A-250VAC-35A-IR-THROUGH-HOLE-/271902224922?hash=item3f4ea2b21a
Is there anything else I'm missing? The goal with all this is to make another "how to" video so I want to make sure I'm not giving people bad advice.
So, it would look something like this (ignore power to radio, didn't have time to wire it):
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@rvendrame said:
@petewill . the MOV goes in parallel with HLK input (and not in series like you did).
It was suggested to use .2A fuses (instead the .75A). And the Thermal fuse should be glued on HLK top (my guess).
Dang, totally forgot about all that in my rush to finish the diagram before lunch ended... That's why you guys design the electronics and I make the videos ;)
How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?
Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?
http://www.ebay.com/itm/5-x-Zinc-Oxide-Varistor-150VAC-15J-1200A-7mm-FREE-SHIPPING-/321024816822?hash=item4abe91f6b6How does this look?
My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA
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@rvendrame said:
@petewill . the MOV goes in parallel with HLK input (and not in series like you did).
It was suggested to use .2A fuses (instead the .75A). And the Thermal fuse should be glued on HLK top (my guess).
Dang, totally forgot about all that in my rush to finish the diagram before lunch ended... That's why you guys design the electronics and I make the videos ;)
How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?
Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?
http://www.ebay.com/itm/5-x-Zinc-Oxide-Varistor-150VAC-15J-1200A-7mm-FREE-SHIPPING-/321024816822?hash=item4abe91f6b6How does this look?
@petewill said:
Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?
As long as you only feed it with 120VAC, there's no issue with that. For those that will feed it with 240VAC, they need to use it with a MOV rated above that.
Cheers
AlPS Here's an option from Digikey: http://www.digikey.com/product-detail/en/MOV-10D241K/MOV-10D241K-ND/2407562
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@rvendrame said:
@petewill . the MOV goes in parallel with HLK input (and not in series like you did).
It was suggested to use .2A fuses (instead the .75A). And the Thermal fuse should be glued on HLK top (my guess).
Dang, totally forgot about all that in my rush to finish the diagram before lunch ended... That's why you guys design the electronics and I make the videos ;)
How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?
Also, I was able to find cheaper varistors. I'm thinking 150VAC should work ok because the HLK is designed to handle 240VAC but maybe I'm off on that?
http://www.ebay.com/itm/5-x-Zinc-Oxide-Varistor-150VAC-15J-1200A-7mm-FREE-SHIPPING-/321024816822?hash=item4abe91f6b6How does this look?
@petewill said:
How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?
The fuse serves two purposes, one to protect if the current draw of the power supply exceeds its rated capacity and the other to blow if the varistor starts conducting a large amount of current in a spike situation. A .75A will still provide protection, but will take a longer time to blow. You want to make sure the fuse doesn't blow because of the in-rush current at start-up, which a fast-blow fuse may do. Typically you want the fuse to be sized at about 150% max of the rated capacity so I would not exceed .3A.
Cheers
Al -
@petewill said:
How necessary are the .2A fuses? I couldn't find any on ebay at a reasonable price. Is the goal of this fuse to prevent large surges (like lightning) from hitting the MOV, or something else? If it's to prevent large surges would the .75A work ok?
The fuse serves two purposes, one to protect if the current draw of the power supply exceeds its rated capacity and the other to blow if the varistor starts conducting a large amount of current in a spike situation. A .75A will still provide protection, but will take a longer time to blow. You want to make sure the fuse doesn't blow because of the in-rush current at start-up, which a fast-blow fuse may do. Typically you want the fuse to be sized at about 150% max of the rated capacity so I would not exceed .3A.
Cheers
AlAs long as you only feed it with 120VAC, there's no issue with that. For those that will feed it with 240VAC, they need to use it with a MOV rated above that.
I am in the USA so I will only be feeding it with 120VAC, but I will make sure to note that anyone using 240VAC will need a different value varistor.
the fuse should be after the varistor in the circuit
Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.
Also, I found some fuses that are rated at 300mA! Not a bad price either!
http://www.ebay.com/itm/Ceramic-Slow-Blow-Fuse-3-6-x-10mm-Axial-Leads-125V-250V-0-1A-6-3A-10-30pcs-/111433875797?var=&hash=item19f1fa0155I think I am almost ready to start ordering parts. I am excited for this build! If anyone else has any feedback please let me know. Thanks!
My "How To" home automation video channel: https://www.youtube.com/channel/UCq_Evyh5PQALx4m4CQuxqkA
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As long as you only feed it with 120VAC, there's no issue with that. For those that will feed it with 240VAC, they need to use it with a MOV rated above that.
I am in the USA so I will only be feeding it with 120VAC, but I will make sure to note that anyone using 240VAC will need a different value varistor.
the fuse should be after the varistor in the circuit
Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.
Also, I found some fuses that are rated at 300mA! Not a bad price either!
http://www.ebay.com/itm/Ceramic-Slow-Blow-Fuse-3-6-x-10mm-Axial-Leads-125V-250V-0-1A-6-3A-10-30pcs-/111433875797?var=&hash=item19f1fa0155I think I am almost ready to start ordering parts. I am excited for this build! If anyone else has any feedback please let me know. Thanks!
@petewill said:
the fuse should be after the varistor in the circuit
Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.
Sorry, the wording I used was unclear and was based on the 120VAC being on the right in your diagram :-). Yes, it is 120VAC -> Fuse -> Varistor -> HLK.
Cheers
Al -
@petewill said:
the fuse should be after the varistor in the circuit
Ok, I'm still a little confused. Are you saying it should be 120VAC -> Varistor -> Fuse -> HLK? Or, 120VAC -> Fuse -> Varistor -> HLK? I thought it was the second one but maybe I misunderstood.
Sorry, the wording I used was unclear and was based on the 120VAC being on the right in your diagram :-). Yes, it is 120VAC -> Fuse -> Varistor -> HLK.
Cheers
Al -
This one is not "safe", but it is an In-Wall AC to DC converter. Transformerless. With a 3A Solid state relay:
The converter output is 3.3V at 100mA and the solid state relay is a Triac.
@ceech said:
This one is not "safe", but it is an In-Wall AC to DC converter. Transformerless. With a 3A Solid state relay:
The converter output is 3.3V at 100mA and the solid state relay is a Triac.
Do you have some shcematic of this board ? I'd like to adapt it for 2 relays
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Can anyone give me ebay-links to the parts I need to order to use the HLK with 230V.
I am getting a little confused about all the links.
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This is the one I sent to be reviewed:
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Ok thanks, but I meant the fuses, varistors and stuff.
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Ok thanks, but I meant the fuses, varistors and stuff.
@Cliff-Karlsson
I haven't tested any of these parts yet but this is what I ordered. I am in the USA so this is spec'd for 120 VAC. If you're using 240 you will need to change the size of the Varistor but everything else should be fine for 240.Varistor for 120VAC - http://www.ebay.com/itm/321024816822?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
73°C Thermal Fuse - http://www.ebay.com/itm/221560426284?_trksid=p2057872.m2749.l2649&var=520415979885&ssPageName=STRK%3AMEBIDX%3AIT
250V 300mA Slow Blow Fuse - http://www.ebay.com/itm/111433875797?_trksid=p2057872.m2749.l2649&var=410420838583&ssPageName=STRK%3AMEBIDX%3AIT
HLK-PM01 - http://www.ebay.com/itm/351418782712?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
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@ceech said:
This one is not "safe", but it is an In-Wall AC to DC converter. Transformerless. With a 3A Solid state relay:
The converter output is 3.3V at 100mA and the solid state relay is a Triac.
Do you have some shcematic of this board ? I'd like to adapt it for 2 relays
@Fabien @DrJeff Here is a link to board and schematic files for the transformerless AC-DC converter:
https://github.com/ceech/AC_SR087 -
@Fabien @DrJeff Here is a link to board and schematic files for the transformerless AC-DC converter:
https://github.com/ceech/AC_SR087
