Sold/Expired SALE: JM-PhD-D1 PWM Hotwire Regulator

[JimmyM]

Hi Jimmy

Put me down for 2 - hopefully your JM-PhD-C1 will be along shortly too !

Now Vlow - Cut-Off set points ? ? ?

Can you and Lux etc. check this for me ?
Errors etc? so I can correct it and then you may want to link to it in post #1
for a guide ?
My best guess for Regulator settings for Vlow - set as CellVlow x Cells

Based on info from AW threads
LiFe and LiMn based on these graphs and 5-10A rate ! and an old test I did

FMA A123 Datesheet


e-Moli Testing RC-Tester WattFlyer.com


Have a good trip and I will let you know my setups when everyone has checked my Vlow chart ! ! !

Cheers
Pete

My personal opinion assuming 12A drain...
eMoli:
3.3V/cell for up to 4S
3.4V/cell for over 4S

A123:
2.8V/cell for up to 4S
2.9V/cell for over 4S.

I'm just adding a little safety factor for larger cell counts.
The nice thing about the A123s is that they hold ~3.3V really well under load. You just have to watch out for the dip in voltage early in the discharge cycle under really heavy loads. However, if you're drawing 45A from your A123s, you shouldn't be using this regulator.

 

[LuxLuthor]

Alan, I was curious how this Canon Powershot SX110 fared with its default lens. I'm still amazed that a 10x zoom lens can take such nice macro shots.

 

[JimmyM]

I'm going to be converting my favorite Mag275 from AWRs hot driver to the JM-PhD-D1. During the process I'll be documenting the whole thing in pictures. I use unprotected Li-Ion D cells. 2 of them. So my settings will be 7.15V Vbulb and 6.0V Vlow. I do have a 3D body, so I may try a 3xLi-Ion Mag275 on 7.15V with a Vlow=9.3V

EDIT: Correction. I'll be using the Philips 5761 instead. It has comparable lumens at 7.2V, uses fewer amps, and has a longer projected life.

 

[JimmyM]

Alan, I was curious how this Canon Powershot SX110 fared with its default lens. I'm still amazed that a 10x zoom lens can take such nice macro shots.

Nice pic too, Lux. It looks like R3 had tombstoned and had to be rewroked. Other than that. This is starting to look like the most recent ones.

 

[LuxLuthor]

Of course I had no idea what "Tombstoning" meant and looked it up. They mention various pastes that prevent this. Naturally, I know nothing about that either.

What I can recognize is a whole quantum leap forward in soldering quality when I compare it to the Hotdrivers.

 

[petrev]

Hi

Thanks for the input to my guide chart - JM and Lux

Corrected and updated with reference to JM, LL and AlanB comments

Cheers
Pete

 

[Alan B]

One thing I note is that Vnominal on NiMH cells are not really 1.4V under load, but closer to 1.2V. The 1.15 value for Vlow is probably too close to that. I don't believe that NiMH are quite as sensitive to overdischarge as the Lithium batteries.

Another way to compute Vlow is (Ncells-1) * Vnom + Vmin. This is the case where one cell drops out first. The values used should be at the load current.

Lux, your Canon is doing quite well. Nice light there. Today's lenses are awesome. I use an 18-200 most of the time that is amazing, and I have a 12-24 that is equal to a prime lens at some focal lengths. The 60mm macro is far beyond the resolution we can use on the web. Many new lenses, especially the zooms, are far beyond most lenses of old. Nikon and Canon make lenses for integrated circuit exposure systems which require manufacturing and performance very near optical perfection, and they have figured out how to do it.

 

[petrev]

One thing I note is that Vnominal on NiMH cells are not really 1.4V under load, but closer to 1.2V. The 1.15 value for Vlow is probably too close to that. I don't believe that NiMH are quite as sensitive to overdischarge as the Lithium batteries.

Another way to compute Vlow is (Ncells-1) * Vnom + Vmin. This is the case where one cell drops out first. The values used should be at the load current.

. . .

Thanks Alan

Not really a big NiMh user so less knowlege in that area - although for 6*NiMh with nominal 1.2V your formula gives 1.15V as the answer. I believe NiMh are less readily damaged by a bit of overdischarge but ? ? ?
Included your input in my chart

Chers
Pete

 

[Alan B]

Pete,

You could put 1.4 or 1.5 as the "fully charged" voltage for NiMH. They are generally in that range when removed from most chargers.

The problem with using these high NiMH "Vlo" values is that under high discharge currents they are reached with cells that are not discharged, and the light will shut off early. They are on the safe side, however.

Jim,

You have mentioned that when the Vlo is reached the light "varies" in intensity. Does it ever shut off? If the flashlight is left on (despite the varying intensity, eg if no one is watching) how are the batteries protected??

 

[JimmyM]

I think 1.15V is way too close to the Nominal voltage of a NiMH cell. Under heavy load, a 2/3A cell would drop too low too quickly. I think that 1V/cell is a better idea. Maybe 1.0V/cell for up to 9 cells, 1.1V/cell for over 9 cells to add a littel wiggle room for a weak cell.

 

[JimmyM]

Jim,

You have mentioned that when the Vlo is reached the light "varies" in intensity. Does it ever shut off? If the flashlight is left on (despite the varying intensity, eg if no one is watching) how are the batteries protected??

There is no "left on" safety. If you reach the low voltage point and just leave the light on, it will continue to pulse. I suppose a few lines of code could be written to shut it off completely if voltage drops below 70 or 80% of the Vlow setting.

Update: There are now 2 low voltage "left on" safeties. Time and voltage based.

 

[petrev]

I think 1.15V is way too close to the Nominal voltage of a NiMH cell. Under heavy load, a 2/3A cell would drop too low too quickly. I think that 1V/cell is a better idea. Maybe 1.0V/cell for up to 9 cells, 1.1V/cell for over 9 cells to add a littel wiggle room for a weak cell.

Hi Jim

Corrected and updated with reference to JM, LL and AlanB comments

Cheers
Pete

ps.
$87

2x JMPhD-D1 $80 + $7 Postage

1. 64633(6xA123) - Set Vbulb 16.4 (16.8 too Hot) Vlow 17.4
2. 64625(5xA123) - Set Vbulb 13.2 (13.6 too Hot) Vlow 14.5



pps. Yes - Good idea to have total cut-off point just in case . . .

 

[pertinax]

I'll take two (for now):


1.) 10.8V, low voltage set to 13.0
2.) 8.4V, low voltage set to 13.0

PayPal coming shortly.

Pertinax

 

[JimmyM]

Sweet

Nice one Jimmy.

I will take Two ( for Now )

#1 Set voltage ? V, low volt: ?V
#2 Set voltage ? V, low volt: ?V

Sorry to be difficult, but at the moment I dont know. But I'm Glad I didn't sell my Fluke 189.

Couple of questions...
How long is the soft start?
Do you still get a soft start if the FET is at 100%?
If the Temp is 70 deg C, and it goes to 25% set O/P...if you turn on and off quickly does the temp feature still kick in when/if the circuit is > 70 Deg C? ( I'm assuming you chose 70 degrees, as the socket may be this hot so the cells ( Li-ion etc,) will still be at 60 deg. or below?
Is the 70 degrees set in stone...or could it be changed in the future. (future hardware/ connection/ software dependant?) or is 70 deg the max heat you would want on the circuit

I will PM later with shipping requirements to the UK, and Voltage settings.

Congratulations...This is Cool!!!! lovecpf

I never got a PM. Did you have any questions?

 

[JimmyM]

pps. Yes - Good idea to have total cut-off point just in case . . .

I'm going to incorporate a bit of code to shut down the light if the voltage drops to a percentage of the Vlow set point. When this point is reached, the light has to be power cycled to get out of that mode. If you power cycle with dead batteries, the light will try to start, then just shutdown again as soon as the voltage drops.

I'm thinking of 87.5% (just because I can multiply by 7 then divide easily by 8).
That works out to...
Vlow = 1.1V/cell, Vshutdown = 0.963V/cell
Vlow = 3.0V/cell, Vshutdown = 2.63V/cell

Does that sound OK?

 

[LuxLuthor]

I'm going to incorporate a bit of code to shut down the light if the voltage drops to a percentage of the Vlow set point. When this point is reached, the light has to be power cycled to get out of that mode. If you power cycle with dead batteries, the light will try to start, then just shutdown again as soon as the voltage drops.

I'm thinking of 87.5% (just because I can multiply by 7 then divide easily by 8).
That works out to...
Vlow = 1.1V/cell, Vshutdown = 0.963V/cell
Vlow = 3.0V/cell, Vshutdown = 2.63V/cell

Does that sound OK?

That will probably be OK. May need to be adjusted after real world testing. Let us know when you have this change in the code to download. I haven't started my *REAL* testing yet, as was waiting on the 5W1k resistors which I just got today.

 

[JimmyM]

That will probably be OK. May need to be adjusted after real world testing. Let us know when you have this change in the code to download. I haven't started my *REAL* testing yet, as was waiting on the 5W1k resistors which I just got today.

I'm not going to be able to get the code tested until next week. Begin your testing when you can. I'll get updated code to you ASAP.

 

[petrev]

Hi Jimmy

Sounds good - once incorporated the failsafe can no doubt be tweaked if necessary after Lux's testing.

That brings me to the next point ? Is the programmer the same as used by AlanB ? AVR I think. ATAVRISP2-ND ? is this the right model number so I can order one from Digikey ?

Cheers
Pete

 

[Raoul_Duke]

I never got a PM. Did you have any questions?

Sorry Dude, My work ( and play) has increased so much in the last 6 months, I barley have time to think...just been away for two+ weeks, half the trip I manned a Frickin big gas installation, Quite literally on my own...with a even Fricking bigger Huge Drilling Rig poking through the middle of mine.... (and the other half Offshore by Day, and out on the town each night )... So Seriously Hectic :twothumbs But Good :devil:

Petrev got it right Here

pps. Yes - Good idea to have total cut-off point just in case . . .

and here

1. 64633(6xA123) - Set Vbulb 16.8 Vlow 17.4

And if I could choose I'd go total cut off would around 15V or a little bit more ( Only using 6 x M1 A123's)

And I guess here is the same for the Uk ?

2x JMPhD-D1 $80 + $7 Postage

And the 'Regulator settings' is cool, I was thinking about weakest cell cappacity ( for Li-mn ), but that just makes it easy

But......I don't know what to do with number two yet, So I'll sleep on it...but still want them both Definitely, and have an true RMS meter, so its not a problem, I should be able to sort it soon. :thumbsup:

 

[Raoul_Duke]

I'm going to incorporate a bit of code to shut down the light if the voltage drops to a percentage of the Vlow set point. When this point is reached, the light has to be power cycled to get out of that mode. If you power cycle with dead batteries, the light will try to start, then just shutdown again as soon as the voltage drops.

I'm thinking of 87.5% (just because I can multiply by 7 then divide easily by 8).
That works out to...
Vlow = 1.1V/cell, Vshutdown = 0.963V/cell
Vlow = 3.0V/cell, Vshutdown = 2.63V/cell

Does that sound OK?

Just read on and that sounds cool. :sick2: