PWM Regulator for Lantern bodies, JM-PhD-X1

[Bimmerboy]

Been lurking this thread for a while, but holding my peace since I don't know when I'll be able to put my money where my mouth is. It'll take a while, but I do want to eventually create a mega-monster... something with WAY too much power for a Mag host to handle. So, I'm throwing my support into the ring.

For people that want up/down brightness buttons or rotary encoders, custom LED indicators, auxiliary thermal sensors, code will be made available.

Very cool, because if I do make some terrifying beast, I'll want a fair amount of the bells and whistles for the "awesome" factor, and to convince everyone around me I've gone completely insane.

 

[JimmyM]

Been lurking this thread for a while, but holding my peace since I don't know when I'll be able to put my money where my mouth is. It'll take a while, but I do want to eventually create a mega-monster... something with WAY too much power for a Mag host to handle. So, I'm throwing my support into the ring.


Very cool, because if I do make some terrifying beast, I'll want a fair amount of the bells and whistles for the "awesome" factor, and to convince everyone around me I've gone completely insane.

I KNOW. Right, bimmer?
If I'm sinking God knows how many hundreds into a 1000+watt monster, that thing is gonna have some bells and whistles. Hell, I want the filament to whine "greensleeves" during start-up. The hardware will be capable of a LOT. However, the things that make it capable of all the bells and whistles, don't add much cost at all.
What is going to cost money... The primary 12V regulator capable of 80 volts will cost about $6 in parts alone. Big FETs are $3-$7 each. It's not gonna be cheap, but will still probably cost less than $100.

 

[Starlight]

Jimmy, single button like the D1 is just right for the standard interface. Under $100 will be fine. You probably better sign me up for serial numbers 001 & 002.

 

[petrev]

I KNOW. Right, bimmer?
If I'm sinking God knows how many hundreds into a 1000+watt monster, that thing is gonna have some bells and whistles. Hell, I want the filament to whine "greensleeves" during start-up. The hardware will be capable of a LOT. However, the things that make it capable of all the bells and whistles, don't add much cost at all.
What is going to cost money... The primary 12V regulator capable of 80 volts will cost about $6 in parts alone. Big FETs are $3-$7 each. It's not gonna be cheap, but will still probably cost less than $100.

Hi Jimmy

Sounds Great

As long as the pads are there for all the extras you can think of - and you write the masses of code needed - I think everyone will be happy.

Cheers
Pete

 

[JimmyM]

I've got a "first pass" at the PCB design. I'm sure I can make it smaller and some of the circuitry will change based on some bench testing to be done. Right now, it's 50mm x 100mm (about 2 in x 4 in)

 

[JimmyM]

I've incorporated relay to disconnect the Vbat sampling resistor divider while off to reduce parasitic losses. I have to order parts for some other testing. Like the 12V primary and 5V auxiliary regulators. I want to try to keep sleep mode power to a minimum. Sleep moce isn't much good if the quiescent current of the onboard regulatos is 100mA.

 

[smopoim86]

This is something I'm definitely interested in. Put me on the list.

Daniel

 

[lunchboxtheman]

I've got a "first pass" at the PCB design. I'm sure I can make it smaller and some of the circuitry will change based on some bench testing to be done. Right now, it's 50mm x 100mm (about 2 in x 4 in)

PCB design looks solid. Once you make sure that it works, you could send it off to a PCB fab service and have it done professionally (which is getting pretty cheap these days). If you did that, you could even use all SMD parts instead of dealing with big through hole parts making it super small and even more awesome!

Keep up the good work. I'm just a programmer, wish I knew more about the hardware side of things.

 

[JimmyM]

PCB design looks solid. Once you make sure that it works, you could send it off to a PCB fab service and have it done professionally (which is getting pretty cheap these days). If you did that, you could even use all SMD parts instead of dealing with big through hole parts making it super small and even more awesome!

Keep up the good work. I'm just a programmer, wish I knew more about the hardware side of things.

I see you've just got here. Welcome.
In my sig is a link to a previous run of regulators that I designed. I had the boards fab'd for that run and will have them fab'd for these too. The professionally done boards are just so nice. It makes reflowing them in my reflow oven almost too easy. Except for the tweezer placement of over 100 components.
This design is 4 layers too, so I can't really do that at home. The high current paths use all 4 layers (2 oz outside, 1 oz inside) with several vias to distribute current amongst the layers.

 

[smopoim86]

What's the current timeframe on these? I'd ideally like one or 2 before the SE Cloudland Canyon meetup. I know it's probably too soon. I'm just itching to get some power behind these big lamps and don't want to blow one in the process.

Thanks
Daniel

 

[JimmyM]

What's the current timeframe on these? I'd ideally like one or 2 before the SE Cloudland Canyon meetup. I know it's probably too soon. I'm just itching to get some power behind these big lamps and don't want to blow one in the process.

Thanks
Daniel

I'm not sure when that is, but these aren't even finished development. Not for months.

 

[petrev]

Hi

Looks Lovely

SE Regional Get-together IV - Cloudland Canyon - Tenn Georgia Ala - May 15 Tentative

😎

Shame it's not in my neck of the woods !

Pete

 

[JimmyM]

Here's another pic of the board. I've added SPI and I2C headers to facilitate things like LCD displays, etc. I've breadboarded most if the circuitry and it all works as intended. I still have to test the power supply section. It has to be able to drop as much as 80V down to 12V and not overheat while running a few extra LEDs or an external LCD. I've got some parts to test a DC-DC converter as well as a linear option.

 

[JimmyM]

More progress in the software area. Working on base functionality. Things get a little noise sensitive when an 80V range in compressed to 1.1V. But I've got things stable with an 80V input and 10V Vbulb. So that's all good.
I'm going to add the low voltage and high temp warning logic next, but want to include compile time options to use the auxiliary outputs for warning LEDs instead of pulsing or dimming the light. I'd like it to be optional to just have the light dim or shutdown and use LEDs for status.

How do you folks feel about external temperature sensors? Thoughts?

 

[Starlight]

Jimmy, I don't think a temp sensor is something I will use.

 

[petrev]

. . .

How do you folks feel about external temperature sensors? Thoughts?

Hi Jimmy

Not essential !
Could be a nice option for people who want to monitor batteries or lamp housing ? Or some such
Low extra cost might consider it ! ? ?

Keep up the great work
Cheers
Pete

 

[smopoim86]

What would it take to have a 12v fan connection to keep the batteries and unit cool off the board? I'm just thinking out loud. I was looking at building a custom box for a par64 and putting a 120mm fan in the rear to keep the case reasonably cool.

 

[JimmyM]

What would it take to have a 12v fan connection to keep the batteries and unit cool off the board? I'm just thinking out loud. I was looking at building a custom box for a par64 and putting a 120mm fan in the rear to keep the case reasonably cool.

The board has an auxiliary outputs that are FET switched grounds. So, depending on how much current it drew, you could use the 12V+ bus from the board to power the fan(+) and connect the Fan(-) to one of the Aux output FETs. How much current it draws is very important. I haven't tested the on-board primary voltage regulator yet. But power dissipation is critical.
With a 60V input, running a 12V fan at 500mA will require power dissipation of 24W. WAY too much. I could add a heat sink, but that drives up cost. I could use a DC-DC converter (switching power supply) for the primary regulator and it could do it without a problem. But that will drive up the cost. As it sits now (with a Linear primary power supply), it can run external LEDs and low power stuff like that.
As it is I'm going to build the output section to allow the use of heatsinks and even potentially fans for the heatsinks, but have an eye on cost.
Can you dig up some specifics on a 120mm fan that you might use? Voltage/Current, etc.

 

[smopoim86]

For a 12v 120mm fan anywhere between 80ma for a light duty fan to around 550ma for a 120x38mm sanAce.

 

[JimmyM]

For a 12v 120mm fan anywhere between 80ma for a light duty fan to around 550ma for a 120x38mm sanAce.

I'm going to be doing some power supply breadboarding and testing in the coming days, so we'll see what happens. But I can tell you that 550mA is too much unless you're running a much lower pack voltage. I want to keep the cost of these things as low as possible. Adding a heat sink to it will only add about $1, but something that size will only be able to dissipate a couple of watts. Using a DC-DC converter will add about $10 (maybe more) to the cost.