Safe In-Wall AC to DC Transformers??
-
@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
-
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
-
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.
-
This is the one I sent to be reviewed:
-
Ok thanks, but I meant the fuses, varistors and stuff.
-
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
-
@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 -
Would this varistor work with 240v?
http://www.ebay.com/itm/10-x-Zinc-Oxide-Varistor-250VAC-60J-2500A-10mm-/260848704608?hash=item3cbbcb5c60 -
@MartinP Based on my limited knowledge, yes, that should work. Maybe someone else can chime in to confirm?
@petewill said:
@MartinP Based on my limited knowledge, yes, that should work. Maybe someone else can chime in to confirm?
I would personally go with a higher voltage rating. Something like 15-20% higher than your normal voltage otherwise you may get regular nuisance trips. So for a 240 VAC system, I would use something close to 290V.
Cheers
Al -
@petewill said:
@MartinP Based on my limited knowledge, yes, that should work. Maybe someone else can chime in to confirm?
I would personally go with a higher voltage rating. Something like 15-20% higher than your normal voltage otherwise you may get regular nuisance trips. So for a 240 VAC system, I would use something close to 290V.
Cheers
Al -
:stuck_out_tongue:RJ_Make
-
Hi all,
I was wondering, I want to be able to adress my blinds using mysensors. Using the relay, radio etc works fine, yet I am still wondering on this power supply. So using the above component I basically prevent fire by using the thermal fuse and an overload by using a regular fuse, the varistor and the HLK.
Now, I am using a Nano (I have still 15 of those) which appear to be using 230mA, the radio itself and a relay. The relay (from the spec sheet) uses 180mA. This should be ok to be used with the HLK shown above. Now, my main concern is, how do you make a all sit together nicely? Is there a PCB type of board you are using? Any pointers welcome :)
Kind regards
Steve
