Welcome Notice

Register Log in

another dimmer smoked today outside thank goodness!...

C

Chuck

Guest
Well, I have one additional so called \"30 amp\" Chinese dimmer remaining
after the prior one smoked. This one had a circuit breaker and it did
go today, but not before it started smoking. As I said, I have a good
Astron power supply on the way to replace, but I still had the dimmer in
place until then and outdoors.

This time, I decided to open it up and see what\'s going on. As others
have said, the Chinese tend to exaggerate ratings so \"30 amp\" was
probably far from it, but I was surprised what I saw internally:

two HY1707 Mosfets
an LM358
a 78L05
a 555 timer

At 12V, 7 amp load, it seems like it should have been able to handle the
load, but I am wondering that since I was driving it with a switching
supply, maybe that somehow affected the dimmer? By the way, the burnout
was one of the HY1707\'s. Perhaps they actually need a heatsink instead
of just being attached to the circuit board?

That\'s absolutely all for the Chinese stuff. I had a constant voltage/
current module on the way, but not even going to open it. Can\'t trust
it anymore.
 
O

ohg...@gmail.com

Guest
On Monday, November 23, 2020 at 3:50:47 PM UTC-5, Chuck wrote:
Well, I have one additional so called \"30 amp\" Chinese dimmer remaining
after the prior one smoked. This one had a circuit breaker and it did
go today, but not before it started smoking. As I said, I have a good
Astron power supply on the way to replace, but I still had the dimmer in
place until then and outdoors.

This time, I decided to open it up and see what\'s going on. As others
have said, the Chinese tend to exaggerate ratings so \"30 amp\" was
probably far from it, but I was surprised what I saw internally:

two HY1707 Mosfets
an LM358
a 78L05
a 555 timer

At 12V, 7 amp load, it seems like it should have been able to handle the
load, but I am wondering that since I was driving it with a switching
supply, maybe that somehow affected the dimmer? By the way, the burnout
was one of the HY1707\'s. Perhaps they actually need a heatsink instead
of just being attached to the circuit board?

That\'s absolutely all for the Chinese stuff. I had a constant voltage/
current module on the way, but not even going to open it. Can\'t trust
it anymore.
A device like that needs a proper heatsink. Even if the metal tab is soldered to the PC it\'s still inadequate for high power applications.
 
C

Chuck

Guest
On 11/23/20 4:09 PM, ohg...@gmail.com wrote:
On Monday, November 23, 2020 at 3:50:47 PM UTC-5, Chuck wrote:
Well, I have one additional so called \"30 amp\" Chinese dimmer remaining
after the prior one smoked. This one had a circuit breaker and it did
go today, but not before it started smoking. As I said, I have a good
Astron power supply on the way to replace, but I still had the dimmer in
place until then and outdoors.

This time, I decided to open it up and see what\'s going on. As others
have said, the Chinese tend to exaggerate ratings so \"30 amp\" was
probably far from it, but I was surprised what I saw internally:

two HY1707 Mosfets
an LM358
a 78L05
a 555 timer

At 12V, 7 amp load, it seems like it should have been able to handle the
load, but I am wondering that since I was driving it with a switching
supply, maybe that somehow affected the dimmer? By the way, the burnout
was one of the HY1707\'s. Perhaps they actually need a heatsink instead
of just being attached to the circuit board?

That\'s absolutely all for the Chinese stuff. I had a constant voltage/
current module on the way, but not even going to open it. Can\'t trust
it anymore.

A device like that needs a proper heatsink. Even if the metal tab is soldered to the PC it\'s still inadequate for high power applications.
I think that\'s why they are burning up, then. Nothing else on the board
was fried, only the one Mosfet.
 
C

Chuck

Guest
On 11/23/20 4:13 PM, Chuck wrote:
On 11/23/20 4:09 PM, ohg...@gmail.com wrote:
On Monday, November 23, 2020 at 3:50:47 PM UTC-5, Chuck wrote:
Well, I have one additional so called \"30 amp\" Chinese dimmer remaining
after the prior one smoked. This one had a circuit breaker and it did
go today, but not before it started smoking. As I said, I have a good
Astron power supply on the way to replace, but I still had the dimmer in
place until then and outdoors.

This time, I decided to open it up and see what\'s going on. As others
have said, the Chinese tend to exaggerate ratings so \"30 amp\" was
probably far from it, but I was surprised what I saw internally:

two HY1707 Mosfets
an LM358
a 78L05
a 555 timer

At 12V, 7 amp load, it seems like it should have been able to handle the
load, but I am wondering that since I was driving it with a switching
supply, maybe that somehow affected the dimmer? By the way, the burnout
was one of the HY1707\'s. Perhaps they actually need a heatsink instead
of just being attached to the circuit board?

That\'s absolutely all for the Chinese stuff. I had a constant voltage/
current module on the way, but not even going to open it. Can\'t trust
it anymore.

A device like that needs a proper heatsink.   Even if the metal tab is
soldered to the PC it\'s still inadequate for high power applications.


I think that\'s why they are burning up, then.  Nothing else on the board
was fried, only the one Mosfet.
Going back to my ham radio days, my 2 meter amps of 100 W had heatsinks
of probably 4x6 and an inch or two thick, IIRC. Sometimes even a fan
too. My guess is that would at the very least be needed for these
dimmers and even that heatsink size will get it no where near say 300
W+. Shame on them.
 
J

John Robertson

Guest
On 2020/11/23 12:50 p.m., Chuck wrote:
Well, I have one additional so called \"30 amp\" Chinese dimmer remaining
after the prior one smoked.  This one had a circuit breaker and it did
go today, but not before it started smoking.  As I said, I have a good
Astron power supply on the way to replace, but I still had the dimmer in
place until then and outdoors.

This time, I decided to open it up and see what\'s going on.  As others
have said, the Chinese tend to exaggerate ratings so \"30 amp\" was
probably far from it, but I was surprised what I saw internally:

two HY1707 Mosfets
an LM358
a 78L05
a 555 timer

At 12V, 7 amp load, it seems like it should have been able to handle the
load, but I am wondering that since I was driving it with a switching
supply, maybe that somehow affected the dimmer?  By the way, the burnout
was one of the HY1707\'s.  Perhaps they actually need a heatsink instead
of just being attached to the circuit board?

That\'s absolutely all for the Chinese stuff.  I had a constant voltage/
current module on the way, but not even going to open it.  Can\'t trust
it anymore.
No UL approval I\'m sure.

Why would you trust it then?

Unregulated electrical junk sold on Amazon can be hazardous to your
house or your family.

John :-#(#
 
P

Phil Allison

Guest
John Robertson wrote:
==================
No UL approval I\'m sure.
** What standard is there for such a device the runs on 12- 24V DC ??

> Why would you trust it then?

** UL does not check for good design or reliability.


Unregulated electrical junk sold on Amazon can be hazardous to your
house or your family.
**True - but this is not a good example for that.


...... Phil
 
J

John Robertson

Guest
On 2020/11/23 3:18 p.m., Phil Allison wrote:
John Robertson wrote:
==================


No UL approval I\'m sure.


** What standard is there for such a device the runs on 12- 24V DC ??

Why would you trust it then?

** UL does not check for good design or reliability.


Unregulated electrical junk sold on Amazon can be hazardous to your
house or your family.

**True - but this is not a good example for that.


...... Phil
Fair enough, under - what is it - 32VAC is unregulated...

John ;-#)#
 
P

Peter W.

Guest
https://www.cui.com/blog/what-is-the-difference-between-ul-listed-and-ul-recognized

https://store.intellaliftparts.com/blog/ul-csa-etl-ce-abbreviations/

Per the NEC and various codes, powered item permanently installed (in the USA) is required to carry a UL/ETL listing.
Technically, any mains-attached (plug-in) item sold to the public (in the USA) is also required to carry a UL/ETL listing. At whatever operating voltage.
UL Listed items made up of sub-assemblies will typically carry UR symbols on those sub-assemblies. Repairs made to such items must be with UR components.

Where this gets cute: That junk from China is sold from, and originates in China, is typically shipped via subsidized Chinese Post, and directly to the consumer - thereby avoiding the letter of regulations and codes. And then there are here-today-gone-tomorrow resellers that get around the code by simply ignoring it. Making their consumers potential victims.

https://www.galco.com/buy/Staco-Energy/3PN1010B?source=googleshopping&utm_source=adwords&utm_campaign=&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fqpZoQpgdsKcuyerBdXTNjaU9OAZzWB_xlXjumLQK-2_lBh92pHqrxoCQPcQAvD_BwE This device carries a CSA mark.

https://www.ebay.com/itm/20Amp-Variac-Transformer-Variable-AC-Voltage-Regulator-Metered-2000VA-0-130V/124023830503 This device does not. Note the difference in cost. That cost is not only for those obscene profits on the part of the manufacturer, but also for proper design, proper testing, basic quality control, insurance and all the other unnecessary niceties avoided by the resellers and their suppliers. So, the bottom line is that you get what you pay for, with all the consequences attached thereto.

Peter Wieck
Melrose Park, PA
 
C

Chuck

Guest
On 11/24/20 9:42 AM, Peter W. wrote:
https://www.cui.com/blog/what-is-the-difference-between-ul-listed-and-ul-recognized

https://store.intellaliftparts.com/blog/ul-csa-etl-ce-abbreviations/

Per the NEC and various codes, powered item permanently installed (in the USA) is required to carry a UL/ETL listing.
Technically, any mains-attached (plug-in) item sold to the public (in the USA) is also required to carry a UL/ETL listing. At whatever operating voltage.
UL Listed items made up of sub-assemblies will typically carry UR symbols on those sub-assemblies. Repairs made to such items must be with UR components.

Where this gets cute: That junk from China is sold from, and originates in China, is typically shipped via subsidized Chinese Post, and directly to the consumer - thereby avoiding the letter of regulations and codes. And then there are here-today-gone-tomorrow resellers that get around the code by simply ignoring it. Making their consumers potential victims.

https://www.galco.com/buy/Staco-Energy/3PN1010B?source=googleshopping&utm_source=adwords&utm_campaign=&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fqpZoQpgdsKcuyerBdXTNjaU9OAZzWB_xlXjumLQK-2_lBh92pHqrxoCQPcQAvD_BwE This device carries a CSA mark.

https://www.ebay.com/itm/20Amp-Variac-Transformer-Variable-AC-Voltage-Regulator-Metered-2000VA-0-130V/124023830503 This device does not. Note the difference in cost. That cost is not only for those obscene profits on the part of the manufacturer, but also for proper design, proper testing, basic quality control, insurance and all the other unnecessary niceties avoided by the resellers and their suppliers. So, the bottom line is that you get what you pay for, with all the consequences attached thereto.
Yes, I definitely see that now. Unfortunately, I had really hoped to be
able to use one of these dimmers because the linear supply is going to
take up more space, but I will not sacrifice my safety for space. I do
wonder about something like PC power supplies. I have some old Dell
ones, many times used for other purposes (those three voltage rails sure
come in handy sometimes), but none that I can see have any UL listings.
I\'ve had desktop PC\'s run for years 24/7 without incident. Anything
that ever went bad was usually memory or hard drives and such. I\'ve had
a lot more trouble with laptops (but still not laptop power supplies...
motherboards!), but that\'s a story for another day.


Peter Wieck
Melrose Park, PA
 
P

Peter W.

Guest
https://www.cpumedics.com/dell-cpb09-000a-350w-power-supply-for-inspiron-530-531-vostro-400-studio-540-xps-8000-8100/?utm_source=googleshopping&utm_medium=cse&_vsrefdom=adwords&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fot0mFXYGy4XdUEa0WJuHrkiygErfrh6ZpwTrkLXFBma4NFd4h_nExoCAlsQAvD_BwE


https://www.cpumedics.com/dell-dk87p-240w-power-supply-with-2x-connectors-6-pin-for-optiplex-3050-5050-7050-inspiron-3668/?utm_source=googleshopping&utm_medium=cse&_vsrefdom=adwords&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fvDBEvqtTAvR17GLXK6yGIeqzOcCCYc4zSUHOW1AaB3vBYqqUvmrwhoCExQQAvD_BwE

If sold in the United States:

There will not be a UL mark on a computer power supply.
There will be a UR mark on a computer powers-supply.
If there is neither, it is a knock-off.

The power-supply is a sub-assembly. Not the main event.

Peter Wieck
Melrose Park, PA
 
C

Chuck

Guest
On 11/24/20 10:05 AM, Peter W. wrote:
https://www.cpumedics.com/dell-cpb09-000a-350w-power-supply-for-inspiron-530-531-vostro-400-studio-540-xps-8000-8100/?utm_source=googleshopping&utm_medium=cse&_vsrefdom=adwords&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fot0mFXYGy4XdUEa0WJuHrkiygErfrh6ZpwTrkLXFBma4NFd4h_nExoCAlsQAvD_BwE


https://www.cpumedics.com/dell-dk87p-240w-power-supply-with-2x-connectors-6-pin-for-optiplex-3050-5050-7050-inspiron-3668/?utm_source=googleshopping&utm_medium=cse&_vsrefdom=adwords&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fvDBEvqtTAvR17GLXK6yGIeqzOcCCYc4zSUHOW1AaB3vBYqqUvmrwhoCExQQAvD_BwE

If sold in the United States:

There will not be a UL mark on a computer power supply.
There will be a UR mark on a computer powers-supply.
If there is neither, it is a knock-off.

The power-supply is a sub-assembly. Not the main event.

Peter Wieck
Melrose Park, PA
Interesting

https://www.pcscsecurity.com/wp-content/uploads/2018/04/ULversusUR_PCSC.pdf

Any external supplies I have do have the UR mark.

Well, thanks for the info. Nice to learn something new everyday. I
will no longer be tempted by the lure of the cheap Chinese eBay junk.

I will say that, by all accounts, this should have been a decent dimmer
judging by the components within but I now believe the lack of
heatsinking was the reason for the failures. The internal design looks
simple enough that, before I trash it, I may try and draw out a
schematic since most of the schematics for this junk don\'t exist.
 
J

John Robertson

Guest
On 2020/11/24 6:42 a.m., Peter W. wrote:
https://www.cui.com/blog/what-is-the-difference-between-ul-listed-and-ul-recognized

https://store.intellaliftparts.com/blog/ul-csa-etl-ce-abbreviations/

Per the NEC and various codes, powered item permanently installed (in the USA) is required to carry a UL/ETL listing.
Technically, any mains-attached (plug-in) item sold to the public (in the USA) is also required to carry a UL/ETL listing. At whatever operating voltage.
UL Listed items made up of sub-assemblies will typically carry UR symbols on those sub-assemblies. Repairs made to such items must be with UR components.

Where this gets cute: That junk from China is sold from, and originates in China, is typically shipped via subsidized Chinese Post, and directly to the consumer - thereby avoiding the letter of regulations and codes. And then there are here-today-gone-tomorrow resellers that get around the code by simply ignoring it. Making their consumers potential victims.

https://www.galco.com/buy/Staco-Energy/3PN1010B?source=googleshopping&utm_source=adwords&utm_campaign=&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fqpZoQpgdsKcuyerBdXTNjaU9OAZzWB_xlXjumLQK-2_lBh92pHqrxoCQPcQAvD_BwE This device carries a CSA mark.

https://www.ebay.com/itm/20Amp-Variac-Transformer-Variable-AC-Voltage-Regulator-Metered-2000VA-0-130V/124023830503 This device does not. Note the difference in cost. That cost is not only for those obscene profits on the part of the manufacturer, but also for proper design, proper testing, basic quality control, insurance and all the other unnecessary niceties avoided by the resellers and their suppliers. So, the bottom line is that you get what you pay for, with all the consequences attached thereto.

Peter Wieck
Melrose Park, PA
Thanks for taking the time to reply to such depth. I will be flagging
this so it is easily retrieved in the future!

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John\'s Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
\"Old pinballers never die, they just flip out.\"
 
C

Chuck

Guest
On 11/24/20 2:36 PM, John Robertson wrote:
On 2020/11/24 6:42 a.m., Peter W. wrote:
https://www.cui.com/blog/what-is-the-difference-between-ul-listed-and-ul-recognized


https://store.intellaliftparts.com/blog/ul-csa-etl-ce-abbreviations/

Per the NEC and various codes, powered item permanently installed (in
the USA) is required to carry a UL/ETL listing.
Technically, any mains-attached (plug-in) item sold to the public (in
the USA) is also required to carry a UL/ETL listing. At whatever
operating voltage.
UL Listed items made up of sub-assemblies will typically carry UR
symbols on those sub-assemblies. Repairs made to such items must be
with UR components.

Where this gets cute: That junk from China is sold from, and
originates in China, is typically shipped via subsidized Chinese Post,
and directly to the consumer - thereby avoiding the letter of
regulations and codes. And then there are here-today-gone-tomorrow
resellers that get around the code by simply ignoring it. Making their
consumers potential victims.

https://www.galco.com/buy/Staco-Energy/3PN1010B?source=googleshopping&utm_source=adwords&utm_campaign=&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fqpZoQpgdsKcuyerBdXTNjaU9OAZzWB_xlXjumLQK-2_lBh92pHqrxoCQPcQAvD_BwE
This device carries a CSA mark.


https://www.ebay.com/itm/20Amp-Variac-Transformer-Variable-AC-Voltage-Regulator-Metered-2000VA-0-130V/124023830503
This device does not.  Note the difference in cost. That cost  is not
only for those obscene profits on the part of the manufacturer, but
also for proper design, proper testing, basic quality control,
insurance and all the other unnecessary niceties avoided by the
resellers and their suppliers. So, the bottom line is that you get
what you pay for, with all the consequences attached thereto.

Peter Wieck
Melrose Park, PA


Thanks for taking the time to reply to such depth. I will be flagging
this so it is easily retrieved in the future!

John :-#)#
I appreciate this too. Further investigation on my part might shed
light on a cause for both of my dimmer failures: too high of input
voltage! Even though advertised as 12-24VDC input, I tend not to trust
this figure and, after looking at the components inside, I think it\'s
12V, period! Unfortunately, the driving supplies I had been using for
this were more like for standard Ham radio, 13.8 VDC. Perhaps this
higher voltage could not be handled by the dimmer components.
 
P

Phil Allison

Guest
Chuck wrote:
============
I appreciate this too. Further investigation on my part might shed
light on a cause for both of my dimmer failures: too high of input
voltage! Even though advertised as 12-24VDC input, I tend not to trust
this figure and, after looking at the components inside, I think it\'s
12V, period! Unfortunately, the driving supplies I had been using for
this were more like for standard Ham radio, 13.8 VDC. Perhaps this
higher voltage could not be handled by the dimmer components.
** You have an obvious overheating failure of one mosfet in a parallel pair.
As mosfets heat up, the on resistance increases by a factor of 2 or more.
So the temp rise does as well.
Having no heatsink at all in that device is nuts.
Bad design, buy something else.


....... Phil
 
P

Phil Allison

Guest
Chuck wrote:
I appreciate this too. Further investigation on my part might shed
light on a cause for both of my dimmer failures: too high of input
voltage! Even though advertised as 12-24VDC input, I tend not to trust
this figure and, after looking at the components inside, I think it\'s
12V, period! Unfortunately, the driving supplies I had been using for
this were more like for standard Ham radio, 13.8 VDC. Perhaps this
higher voltage could not be handled by the dimmer components.
** You have never posted what PSU voltage you have been using ???

The rating of 12-24V applies to the LED array it is driving.

You cannot use a 24V supply, connect a 12 V LED array and set the control half way.


...... Phil
 
C

Chuck

Guest
On 11/24/20 5:38 PM, Phil Allison wrote:
Chuck wrote:


I appreciate this too. Further investigation on my part might shed
light on a cause for both of my dimmer failures: too high of input
voltage! Even though advertised as 12-24VDC input, I tend not to trust
this figure and, after looking at the components inside, I think it\'s
12V, period! Unfortunately, the driving supplies I had been using for
this were more like for standard Ham radio, 13.8 VDC. Perhaps this
higher voltage could not be handled by the dimmer components.

** You have never posted what PSU voltage you have been using ???

The rating of 12-24V applies to the LED array it is driving.

You cannot use a 24V supply, connect a 12 V LED array and set the control half way.


..... Phil
So, it could have been either lack of heatsinking, my 1.8V overvoltage,
or both?

Thanks for the clarification on the 12-24V. I certainly didn\'t know this!
 
P

Phil Allison

Guest
On Wednesday, November 25, 2020 at 11:35:21 AM UTC+11, Chuck wrote:
On 11/24/20 5:38 PM, Phil Allison wrote:
Chuck wrote:


I appreciate this too. Further investigation on my part might shed
light on a cause for both of my dimmer failures: too high of input
voltage! Even though advertised as 12-24VDC input, I tend not to trust
this figure and, after looking at the components inside, I think it\'s
12V, period! Unfortunately, the driving supplies I had been using for
this were more like for standard Ham radio, 13.8 VDC. Perhaps this
higher voltage could not be handled by the dimmer components.

** You have never posted what PSU voltage you have been using ???

The rating of 12-24V applies to the LED array it is driving.

You cannot use a 24V supply, connect a 12 V LED array and set the control half way.


..... Phil

So, it could have been either lack of heatsinking, my 1.8V overvoltage,
or both?

** Was you 8A current figure when the controller was set to full ?
> Thanks for the clarification on the 12-24V. I certainly didn\'t know this!

** Yes - it is missing data in the advertising.

A PWM controller is *not* a voltage regulator, merely a \" time division\" current reducer.

If the voltage is a little high, the current will be way higher.


....... Phil
 
Toggle Sidebar

Welcome to EDABoard.com

Sponsor

Top