Hi,
I'm Felix a 19 year old aerospace student and i have a vintage lamp for my bureau. I got it from the office where my mom used to work, why i got it is also the problem I'm having with it. It gets really hot. There is an old 50W transformer in the base and there is an halogen bulb inside. It even says on the bottom that the lamp is an fire hazard. So i want to convert it to led but without irreversibly modifying the lamp. To do this i want to put a PCB with an rp2040zero and a power supply in the base and a PCB in the head of the lamp. These two are connected by a single wire and a common ground of the arm of the lamp. So i need to transfer signal over the power line. With Gemini, I came up with a design and I'm curious about the potential of the design? at the moment its just the rp2040-zero's and two max20340 IC's. Would you thinks this would work? And what type of LEDs should I use in the lamp. I was thinking about SK6812 RGBNW chips. So i could change the temperature of the light.

If you have any suggestions I'm happy to hear it,
Kind regards Felix

 

There are LED bulbs in all shapes and sizes, so have you identified potential replacement bulbs?

I'm curious about the transformer, what is the current bulb's voltage rating?

Have you measured the voltage at the bulb socket? is it AC or DC?

Show us some pictures of the details, the bulb, socket, transformer and so on.

Anything that plugs into a wall outlet really must ensure all exposed metal parts are grounded too.

Finally, why all the computing power, this is just a desk lamp?

 

what is the purpose of RP2040 and MAX20340 in a desk lamp? if wanting to control it, an ESP32 or ESP01 may do the job and connect to network.

 

what is the purpose of RP2040 and MAX20340 in a desk lamp? if wanting to control it, an ESP32 or ESP01 may do the job and connect to network.

Its going to be a bit over engineered. But the only place to put a button or rotary encoder to control the brightness and color temp is at the base. And i don't want to replace the wires that are going through the arm of the lamp. So with the MAX20340 i might be able to get power and signal over 1 wire. So 1 rp2040 controls the LEDS and 1 rp2040 takes the input such as how bright the LEDS need to be and sends it to the other one. I could control it through Bluetooth or WiFi but i rather make it so it doesn't need to have any wireless connections.
kind regards,
Felix

 

There are LED bulbs in all shapes and sizes, so have you identified potential replacement bulbs?

I'm curious about the transformer, what is the current bulb's voltage rating?

Have you measured the voltage at the bulb socket? is it AC or DC?

Show us some pictures of the details, the bulb, socket, transformer and so on.

Anything that plugs into a wall outlet really must ensure all exposed metal parts are grounded too.

Finally, why all the computing power, this is just a desk lamp?

Hi Futurist,
I think the transformer output is 12VAC 50hz 50W. With a gy6,35 socket. So yes i just could just replace the bulb and maybe the transformer. But that is a little boring so its more a project than an efficient solution. And yes the RP2040 are a little overkill but I have done some simple project with just LEDs and switches on them so it was the first (and only) thing that came up.
Kind regards,
Felix

 

Hi Futurist,
I think the transformer output is 12VAC 50hz 50W. With a gy6,35 socket. So yes i just could just replace the bulb and maybe the transformer. But that is a little boring so its more a project than an efficient solution. And yes the RP2040 are a little overkill but I have done some simple project with just LEDs and switches on them so it was the first (and only) thing that came up.
Kind regards,
Felix

https://www.buylightfixtures.com/LE...nt-Light-Bulbs-3-Watt-5000K.aspx?gad_source=1

Fine, if the project interests you then that's reason enough.

 

Finally, why all the computing power, this is just a desk lamp?

I just have to laugh.

In 1978 I went to work at Digital Equipment Corp. My team of 6 programmers shared a PDP 11/34 16-bit 1.5 MHz CPU doing software development.

Now, it apparently takes a dual processor 133MHz 32-bit CPU to turn a light on and off.

 

I just have to laugh.

In 1978 I went to work at Digital Equipment Corp. My team of 6 programmers shared a PDP 11/34 16-bit 1.5 MHz CPU doing software development.

Now, it apparently takes a dual processor 133MHz 32-bit CPU to turn a light on and off.

Yes, I'm sure you recall water cooler conversations too about the "Hot, hairy golf ball" as we programmers like to do when future gazing.

I recall reading predictions about light bulbs with computers in back in the 70s and 80s in magazines like Byte, Scientific American and so on, these predictions were not unreasonable given Moore's law but were not taken too seriously, how wrong I was.

 

he did mention SK6812 LEDs which are RGB so some sort of control is needed. but there are ready made RGB light bulbs. so i m guessing that goal is not the modification itself but the learning experience.

 

What do you guys think of using the lamp body as the -ve in his circuit? is that not frowned upon when the lamp body is also the outlet ground?

 

he did mention SK6812 LEDs which are RGB so some sort of control is needed. but there are ready made RGB light bulbs. so i m guessing that goal is not the modification itself but the learning experience.

exactly, its more like: look what i made and check out how many unnecessary functions it has and how complicated it is in comparison with changing the light bulb.

 

What do you guys think of using the lamp body as the -ve in his circuit? is that not frowned upon when the lamp body is also the outlet ground?

The outlet plug doesn't have a ground/earth pole. I live in the EU so it might differ from the US or other countries.

 

don't feel left out

 

The outlet plug doesn't have a ground/earth pole. I live in the EU so it might differ from the US or other countries.View attachment 358231

OK, so does the bulb socket's -ve terminal connect to the lamp chassis?

 

OK, so does the bulb socket's -ve terminal connect to the lamp chassis?

for what i know the bulb is connected to 1 wire and the arm. The arm is on a plastic ball pivot. and those two get connected to the (i think) transformer. And that goes straight to the switch and outlet. The lamp has two modes, blinding and a little les blinding. So the three wires comming out of the transformer are common ground and two for the different light setting.

 

for what i know the bulb is connected to 1 wire and the arm. The arm is on a plastic ball pivot. and those two get connected to the (i think) transformer. And that goes straight to the switch and outlet. The lamp has two modes, blinding and a little les blinding. So the three wires comming out of the transformer are common ground and two for the different light setting.View attachment 358239View attachment 358240

OK so fine, looks like using the chassis as your -ve is a non-issue then. Have you not considered re-threading the wire? Since it will no longer be supplying current to a 50W bulb ( ≈ 4 amps) you can use a smaller gauge wire and potentially thread a multi-core finer cable through.

Perhaps find an old thin USB cable, cut the ends off and you're good to go, you can get these in 28AWG with at least 4 cores.

That will eliminate the effort to somehow modulate the DC supply...

 

OK so fine, looks like using the chassis as your -ve is a non-issue then. Have you not considered re-threading the wire? Since it will no longer be supplying current to a 50W bulb ( ≈ 4 amps) you can use a smaller gauge wire and potentially thread a multi-core finer cable through.

Perhaps find an old thin USB cable, cut the ends off and you're good to go, you can get these in 28AWG with at least 4 cores.

That will eliminate the effort to somehow modulate the DC supply...

I was thinking about it but the lamp is pretty expensive so i don't want to remove things and keep it as much original as possible. With an power line communication setup and two pcb's its possible to change it back to the original state. (and i like the challenge of making a conversion that modifies the original the least

 

I was thinking about it but the lamp is pretty expensive so i don't want to remove things and keep it as much original as possible. With an power line communication setup and two pcb's its possible to change it back to the original state. (and i like the challenge of making a conversion that modifies the original the least

Fair point, good luck, I'm interested to see progress here.

I bought an old 1930s table lamp about ten years ago (in an Arizona "antique" store), a statue of a lithe female with a shade on top. It had old worn out fabric covered wire, so I bought some replacement wire but then got distracted and never did finish the upgrade.

I have old radios here too (one is 100 years old "Silvertone" a neutrodyne circuit) and keep promising to get them going, I think its right to retain as much of the original as you can in a project like yours, so keep us posted.

 

I was wondering if anyone can tell me if this diagram would work for my design use? The two circled connectors are the connection between the two pcb' s. I made everything with Gemini and the max20340 datasheets. Is there anything i need to take into account when i make the layout and wiring of the actual pcb?

 

Cool but this is something a modern 8-bit pic could easily do but that's out of the box for today's lame AI helpers that have no understanding, only examples of what's popular in social media.