so we we will follow:
Dia:17mm, Height(about11MM)
Current:regulated 4A boost
PWM:More than 4KHz
Voltage: 4.2V
Modes: Moon0.5% -Low5% – Mid30% – High100%
Memory mode
With Temperature thermal protection (70C)
Low voltage protection (2.8V)
sounds good bill, cant wait
Can you add a resistor mod to reduce max current to 3.0 or 3.5A?
Also low voltage protection at 3.0V would be nice
now we are arrange the production already,it will some after 10days
Bill and I have been in contact via PM.
Update from Bill:
Hi relic
thanks for your reply
today i talked with my factory again,he told me,if according the request,the height will be about 11MM already,is it ok?
so we we will follow:
Dia:17mm, Height(about11MM)
Current:regulated 4A boost
PWM:More than 4KHz
Voltage: 4.2V
Modes: Moon0.5% -Low5% – Mid30% – High100%
Memory mode
With Temperature thermal protection (70C)
Low voltage protection (2.8V)
We need to design the board,so it will take some more days,maybe it will take 15days
once i got the them,i will send one to you for testing,ok?
My responses:
Hi Bill,
- The height is OK.
- Can you lower Moon to 0.2%? The idea for Moon mode is to be about as bright as a full moon, no brighter.
- I think Atmel is preferred because of the widespread use. Would this be possible?
I’d be happy to test the board, when it’s ready I’ll provide my shipping address. Thanks! Relic
Hi Bill, Regarding the height, make sure there are no components within about 1mm of the PCB edge. The inside of the flashlight pill is smaller than 17mm.
That means the component space is about 15mm in diameter.
Best Regards, Relic
Looking good!
Can a trim pot be added instead? Then the user can dial in the current. Id call that a great feature.
What do others think?
The trim pot would have to be a high current type, which are not feasible for this product (size and cost). The best option we have to tweak the current is sense resistor mods. I will verify the current limit method with Bill to ensure we will have resistors to mod. 
Edit: PM sent to Bill.
That would be really cool, great idea.
One caveat I see is loosing track of the number of turns and messing up the current.
Are you sure? Neither the input nor the output current passes through the sense resistors/trimpot.
Wouldnt that depend on the design? Some drivers even have a feature to add an external pot to use as a dimmer.
If this isnt feasible, would a 3 or 4 mode user programmable ramping feature be a possibility? These already exist and work really well. :bigsmile: The user programs the set point during the ramp sweep in each mode from low to high and the driver saves it for each mode. That way the user can set each mode to any level they want and change them at will.
I couldnt find a youtube to demonstrate this.
Hmm, ramping driver… that would be interesting.
Yes, with a slightly different design, we could use a trimpot to adjust the level. The trim pot adjusts a reference Voltage that is used for the current sense feedback. It complicates the design and I’m concerned about board space.
I prefer the ramping driver over a trim pot. Levels can be adjusted any time without tearing down the flashlight.
I’ll send another PM to Bill, see what he thinks.
Good idea FlashPilot! 
Thanks Relic. Please mention 4 modes, each with ramping and user saveable setpoint for each. I think that should satisfy just about everyone.
Is there a suggested way to enter the ramping config mode? A series of fast clicky presses? From there, it might get confusing as to which mode you are programming.
I’m thinking we only need two programmable modes; Med and Low. High is 100. Moonlight is 0.2, Low and Med can be set using the ramping method.
What do you think?
> 4 modes: moonlight; 0.1, low; 1, med; 30, high; 100
Start DIM increase to BRIGHT
(others differ —- I notice how the sequence gets flipped from one person’s list to the next)
I’ll stay interested as long as dim-first-increase-to-bright is an option.
Yes, 3-4 user groups to satisfy different customers with different mode changing requirements.
An example:
Group 1:
High: 100%
Med: 30%
Low: 4-5%
Moonlight: 0.1%
Group 2
High 100%
Mid 30%
Low 5%
Group 3
High 100%
Low 10%
Group 4
Ramping
Or you could set up different group modes with different power settings, this will make the driver more versatile and more adaptable to different hosts, i.e a tube light wouldn’t handle a high 4A, 2A would be more reasonable.
Group 1:
High: 100%
Med: 30%
Low: 4-5%
Moonlight: 0.1%
Group 2
High: 75%
Med: 20%
Low: 4-5%
Moonlight: 0.1%
Group 3
High 50%
Mid 15%
Low: 4-5%
Moonlight: 0.1%
Group 4
Ramping
Or a combination of both, thus we’ll have 1 driver that could suit all our needs. 
Er, I’ve got an almost tube light build on the cards where 4a is not going to be enough……
( ok, its a p60 sized host, my point remains it needs at least 4.2a preferably closer to six amp) 
I like the previous 4 mode driver. Simple and easy.
But, it could be awesome if it used ramping to set the modes if it were combined with a decent UI. Then it would be better to have 5A and have all modes fully adjustable.
It could feature several groups too.
Group 1: 1 mode
Group 2: 2 modes
Group 3: 3 modes
Group 4: 4 modes
Group 5: 5 modes
THAT should keep everybody happy! 1-5 groups, and all modes fully adjustable from 0,1-100%
(okay, there would be no blinky modes, but there are enough lights out there with those)
Default setup could be group 4 with: Moon0.2% -Low3% – Mid25% – High80% (5A=100%)
So, choose group 1 then you lumatic.
Why not make it completely (and easily) customizable for everyone’s use? High to low or low to high, and with any possible power percentage in each mode.
UI:
4 modes with memory. Click within 1 second for next mode.
- mode 1 - 0-100%
- mode 2 - 0-100%
- mode 3 - 0-100%
- mode 4 - 0-100%
To set each mode percentage: Fast triple click after 5 seconds in the desired mode to begin 10 second ramp sweep. Sweep starts out at 0% and slowly progress to 100% output. Single click at any point during the 10 second sweep to save the desired brightness. If single click not received during the 10 second ramp sweep, driver flashes twice at end of sweep to indicate 100% has been reached and is saved at 100%.
This will allow each of the 4 modes to easily be set at any percentage by the user. Super simple, super easy… and will satisfy everyone.
Ramping to set modes sounds great, if not too hard to make