Dec 9,2022
About the low voltage Edison bulbs, the driver is much more important. If there is only a DC requirement, no AC requirement, then the power should be only DC, for example, 12VDC, 24VDC, 36VDC. If there is also AC output, for example, 12V DC/AC, 24V DC/AC, then there may be a problem!
We are well-known designers of 12v vintage led bulbs. One of our customers asked us for 12v Edison light bulbs, they are A19 5W 12VDC, ST64 5W 12VDC, and C35 3W 12VDC. In order to meet 12V AC power too, our engineer did all of the 12V DC/AC, so they can work under both 12AC and 12DC. However, there is a problem happened for this 12VDC/AC low voltage led bulb because 12VAC limits the function of 12VDC, so when the input power is three times more than the low voltage led bulb, the 12V DC/AC driver will start its protection system, and turn off. After a lot of testing and analyzing, our engineer found this problem and did samples of 12V DC to our customer for testing, and testing was passed.
The email communication with the customer is as below for details:
(There is a date also, from the bottom to the top).
Date: 2018-04-23 15:38:09
Dear David,
Thank you!
We will start production of the 12V bulbs, C35, ST64, and A19, same as the sample we sent to you. Thank you!
Regards!
Alex
At 2018-04-23 06:37:05
Hi Alex,
Sorry for the late reply.
Yes, all is good. Please proceed with production.
Regards,
David
On 22 Apr 2018, at 12:29 pm
Dear David,
Good morning!
How about the testing? shall we start production of the 12V bulbs, C35, A19 and ST64. Thank you!
Regards!
Alex
At 2018-04-10 13:43:08
Hi Alex,
This is good news. And makes sense to me.
Yes please, send me these samples and drivers.
Regards,
David
On 10 Apr 2018, at 11:12 am
Dear David,
After testing analyzing the drivers from you, the reason is that our led bulb does not match the driver much well.
So sorry for this problem!
Regards!
Alex
At 2018-03-23 06:49:24
Hi Alex,
I’m sending you good globes, failed globes, and the 6W driver that went missing.
You already have the other drivers so no need to send them again.
Regards,
David.
On 22 Mar 2018, at 4:53 pm
Dear David,
Thank you and sorry for this problem!
Could you please send the drivers, some good quality 12V globes for testing, some damaged 12V globes for analyzing?
Regards!
Alex
At 2018-03-22 12:10:02
Hi Alex,
I have finally received new drivers to replace the units I sent you.
I recreated the tests and took videos of the globes flashing with the various drivers and quantities of globes.
I will have to get Phil to set up a link so that you can download them as they’re too large for the email I think.
I have also now got some more damaged globes.
So I will send these globes to you.
Regards,
David
At 2018-03-19 05:29:05
Hi Alex,
You should also have a 6W driver.
I am getting more drivers, as I sent the ones I had to you. I will match your number of bulbs per driver.
Have you tested say 2 globes on the 15W driver for example?
It’s very frustrating that you can’t repeat my results.
I had problems within 10 minutes or less.
Regards,
David
On 17 Mar 2018, at 3:34 pm
Dear David,
We received 3pcs power from you, they are 12W, 50W and 40W.
Our Led bulb A19 and ST64, input is 12V 360mA.
Testing result as below:
and turn the dimmer to its minimum, and then turn the dimmer to Max., all the led bulb is not working, when we cut off
the power supply and start the electricity supply again, the led bulbs are working again. Because when the dimmer is at its maximum,
The power starts its protection, so not working, we have to restart the electricity power supply to make it reworking.
You mentioned you have some led bulbs damaged, our engineer said it is better to send us back the damaged led bulbs,
we have to check and analyze the defects. Thank you!
Any questions please feel free to let us know.
Regards!
Alex
At 2018-03-07 11:36:09
Hi Alex,
Sorry not to reply to you sooner.
I have been testing the 3W candle globes, qty 1 & 2 on the 6W driver, and qty 3 & 5 on the 15W driver.
There are no problems with these at all from my testing.
Yes, I will send you drivers.
Regards,
David
On 7 Mar 2018, at 11:19 am,
Dear David,
Could you please send us your drivers? We will test at our factory. Thank you!
Regards!
Alex
———————————————————————————————————————————————-
Dear David,
Sorry for this problem!
under high current without being damaged. How do you think? But our led bulb does not work with a current lower than 360mA.
Regards!
Alex
At 2018-03-06 12:45:53
Hi Alex,
Normally we would spec a CV driver with at least 25-50% more wattage than required.
I.e., you would use a minimum 8W driver for a 5W globe so that the driver isn’t running too hot all the time.
If you say I can’t do that because the 8W driver could potentially deliver 666mA and this may damage the globe, then I don’t understand how it would ever work.
I’m currently testing the 3W candle on the 6W AcTEC driver and found no problems after 2-3 hours.
I want to test more, but this is what I would expect.
Phil said he has the expectation that as long as a customer has a driver with enough power, then he can run 200W of globes on one driver.
I think, however, that on many occasions one globe-one driver would be acceptable.
I think at least we need to replace the ST64 and GLS globes and design them so they withstand high current.
If you think this is possible, I can send a range of drivers to you.
Regards,
David
On 6 Mar 2018, at 2:20 pm
Dear David,
1. The 3 drivers you are using is constant voltage driver, but not constant current. If the current requirement from the led bulb is too high, the led bulb will not light on; if the current requirement from a led bulb is too low, the led power temperature will be high, high temperature will increase the current, this will cause the led bulb damage.
2. Our 12V led is constant voltage, not constant current. The lowest current required for the led bulb is 360mA, the rated current for 5W led bulb is 410mA, our engineer suggests the current range is 360-500mA for 5W constant voltage. So the driver you are using has to meet this requirement of 12V 360-500mA for each bulb.
3. Our engineer said we will make the 12V led bulb constant voltage and constant current so that the led bulb can not be damaged, the current range is 360mA to Highest.
4. If you could send us the drivers that you are using most, our engineer will test and tell you how many bulbs will be applied to one driver.
Any questions please feel free to let us know. So sorry for this problem!
Please tell us how shall we handle this issue. Please tell us the defects quantity, we will replace to you.
Regards!
Alex
At 2018-03-06 09:09:45,
Hi Alex,
Thanks for the reply.
I did not check the C350403 as I only had E27 sockets to check.
I’ll have look at them though as well.
Regards,
David
On 6 Mar 2018, at 12:04 pm
Dear David,
So sorry for this problem!
What I understand is our 12V globe has problems as below:
I have submitted this issue to our production and engineer, I will reply to you as soon as possible.
Regards!
Alex
At 2018-03-06 07:44:09,
Hi Alex,
So I’ve been testing the 12V globes with various LED drivers.
I used the Meanwell PWM-40 12V, AcTEC Q3 50W 12V, AcTEC Q4 6W 12V & 15W 12V. All constant voltage style.
I have included the datasheets for you to look at.
For each driver, I tested various globe quantities, well under the limit of the wattage rating of the driver. The closest one was the 5W globe on the 6W driver.
The AcTEC drivers were tested first and on each occasion, the globes started to cycle on and off after a few minutes.
The Meanwell test saw the globes turn off after a few minutes and not turn on again until I cycled the power to the driver, after which they turned off again.
I noticed the globe screw caps were very hot to touch I guess >60 degrees.
I used new globes each time but also discovered some globes were permanently damaged.
We have had a few customers with similar issues which is why I started testing.
I have some ideas, but I would like to hear what your engineers think might be happening.
Regards,
David