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Sold/Expired Pre-Order JM-PhD-X1, PWM Lantern Regulator


Flashlight Enthusiast
Aug 30, 2006
Boston, MA, USA
Pre-Order is now OVER
I'm pleased to announce the sale of the JM-PhD-X1. This regulator design is primarily for those of us with SERIOUS power regulation requirements. The folks that build lantern style lights using 600W+ aircraft lights.
Here is a picture of the PCB design. I will replace it with a picture of the actual regulator once they're built.


This is another regulator design based on my previous PhD-D1 and the work linked to below.
This has been built based on my previous JM-PhD-D1 found HERE.

The feeler thread for the PhD-X1 can be found HERE. This discussion is an evolution. Many many options were discussed, but it was whittled down to something more simple and robust rather than something super feature laden and expensive.

How it works: It uses PWM (Pulse Width Modulation) to control the RMS voltage to the bulb. By turning a switch (an FET) on and off several times (244Hz) a second, the "effective" voltage that the bulb sees can be controlled. The bulb is still receiving the full battery pack voltage while the switch is on, but it's not on for the whole time. The frequency of the PWM and thermal mass of the filament prevent flicker. It can only control output voltage less than or equal to the pack voltage. It cannot boost battery voltage.

-Dimensions: 69.6mm x 55.5mm (2.75 IN x 2.19 IN)
-The "Drive Section" can, at the user's option, be separated from the "Control Section" by the user to allow remote mounting of the high current components.
-Voltage input range is 17V to 70V.
-Current carrying capability: Projected Minimum 40A RMS.
-Dual 3.9mOhm FETs with Heatsinks (WARNING: The heatsinks are electrically connected to the "Bulb" connection on the regulator board)
-High current connections: Mounting holes for ring terminals (#8 screw) or soldering.
-Auxiliary PWM outputs for future use of warning LEDs or FANs. Enabled by custom programming.
-Auxiliary power connections allow up to 400mA at ~11.4V to drive outboard electronics. amp/volt displays, fans, LEDs, etc.
-Solder pads for the control button (button not included).
-2 Auxiliary micro-controller pads that can be enabled for other functions with custom programming.
-Removable/replaceable micro-controller (Atmel ATTiny84).
-1 dual switch DIP switch for future use with custom programming.
-FET drive disable jumper. This is used to disable the output during programming. If the regulator is programmed while the jumper is in place, it could blow the bulb.
-There are no user adjustable pots on the board. ALL changes must be made in software and programmed into the board.

-------- BEGIN WARNINGS----------
This regulator can work with voltages in excess of 48V (70V maximum). These voltages can be dangerous. The user/purchaser accepts FULL responsibility that all proper safety precautions are taken. If you're not familiar with working with these voltages, please do not experiment with this regulator.

The heatsinks on these regulators are electrically connected to the "BULB" connection on the PCB and can carry the full battery voltage at times. If the heatsink(s) is/are shorted to ground, the bulb will receive the full battery voltage and may be damaged or explode. If the heatsink(s) is/are shorted to other components on the board, it will destroy the board, possibly beyond repair. It is up to the user to ensure that the regulator is mounted in such a fashion as to allow electrical isolation if the heatsinks.

The bottom of the regulator board has connections that carry the full battery voltage. These must NOT be allowed to touch anything electrically conductive or a short circuit may be caused potentially destroying the regulator and/or causing a fire.

Parasitic current ("Off mode" current). While the regulator is shut off, it will still drain a little current from your batteries. It's about 3mA.

Bulb Disable Jumper: You MUST remove this jumper if you are programming this regulator while it is installed in the light. You could cause bulb damage if you program the regulator with this jumper in place.

-------- END WARNINGS----------

Software Options:
Currently, the software is written to allow the below options.

-Multi-level, single button interface. 1 push turns the light on to the first level or the last level used (See config options). Up to 5 levels can be specified in the configuration. Pressing and holding the button for about 1 seconds will shut down the regulator.

-Memory Start: If used, the regulator will start to the level that was last in use when it was shut off.

-Low voltage warning: At a programmed voltage (selected at purchase) the bulb can either pulse or dim to indicate a low battery voltage condition exists.

-Low voltage shutdown. At a user selected percentage of the Low Voltage Warning, the regulator can shutdown. In addition to this, the user can select a time (in seconds) the the low voltage warning can be active before the regulator shuts down.

-Over Temperature warning/shutdown: This is here to protect the electronics. This feature is not intended to protect your bulb, wires, battery, or lantern body. If activated (at 80 deg C), it will dim the bulb to 35% of the active voltage level. It will stay there for up to 30 seconds. If the regulator is still above 80C after 30 seconds the regulator will shut down.

-Soft start: 3 user selectable softstart options are available. Slow, Medium, and Fast. Slow is good to use if you are really over driving your bulb and want to be as gentle as possible. Medium is a good selection for most users. Fast will start the bulb in about 100mS.

Softstart: Slow, Med, Fast
Low Volt Warning: Pulsing or Dimming

Customized programming: At this time I cannot offer extensive custom programming. This includes incorporation of onboard hardware (auxiliary uC ports, thermal sensors, PWM outputs, DIP switch for selectable options, etc).
If you want your regulator reprogrammed with new voltages and are unfamiliar or uncomfortable doing it yourself, I will accommodate you for free. You will pay return shipping. That being said, I may offer additional functionality in the future with new firmware. These new releases are free and I'll reprogram/upgrade your regulator for you or send you the newer code if you want to do it yourself. Again, you will pay return shipping. However, if the regulator is somehow defective or otherwise "misbehaving", I will work with you to make it right and I will cover return shipping.

Connection diagrams, instructions, and firmware can be found here:

Ordering/Shipping information:
Currently, I am unable to get all the parts necessary to build these (1 part on backorder until January 2011). I have ordered all the parts necessary. So I'd like to offer a pre-order/pre-pay sale on these regulators.

Effective now, each regulator will cost $80.00 USD
These regulators are larger than the PhD-D1 and cannot be shipped via padded envelope. I will ship them via USPS (US Postal Service) Flat Rate Box.
United States: $6.00 USD
Mexico/Canada: $12.00 USD
All others: $15 USD
You will only be charged for shipping once per order. I imagine I could fit 6 or so regulators in a box. Maybe more.
PayPal Fees: (Fees apply to entire amount sent. Regulators and shipping combined)
Credit Card PayPal transfers, please add 3%.
Non-US purchases, please add %4
If Credit Card AND Non-US purchases, please add 7%

Only 25 of these will be made.

Regulators will be programmed and shipped as soon as the last part is installed. All regulators will be shipped with the most current firmware.

Payment for Orders is being accepted NOW.
I only accept PayPal payments. Please send PayPals to [email protected]

Revision 2 of the firmware has been released with new features and a small improvement here and there.
*** WARNING ***
You MUST use a Rev 2 options file with this release. You CANNOT use your Rev 1 options file.

Rev 2a - All functionality found in Rev1 Plus...
- Low Voltage Latch mode that hold the low voltage waning mode even if the battery recovers. This can prevent a heavyily loaded pack from "fooling" the low voltage sensing and causing the light to appear to blink.
- Additional Over Temp warning (OT_TYPE = 2). Shuts down the bulb and uses the Auxilliary PWMB Output to drive the ground leg of an LED as a flashing Warning.
- Additional Low Voltage warning (LV_TYPE = 3). Shuts down the bulb and uses the Auxilliary PWMA Output to drive the ground leg of an LED as a steady Warning.
- Configurable duty cycle of PWM A & B Outputs when used as Overtemp or Low Voltage warnings.
- A Mode to allow the Aux PWM A output to control a relay that completely disconnects the regulator power supply. Wiring details can be found in my web site above.
- In Rev1, when the main output was shut down due to overtemp/low voltage the output was actually reduced to 1/4095th duty, not truly off, before it was completely shutdown ~4mS later and the regulator was put to sleep. This also occurred between the time you held in the button to shut it down and releasing the button. Now the output is reduced to zero output during these short time periods. Don't worry. When you shut down your regulator with Rev1 it is actually shut down. It just went into an almost 0 duty cycle for a short period beforehand.

Here are the new programming options that you should cut and paste into your order.

Bold items are default settings.
Please cut and paste this into your post and edit the voltages/options you desire for each setting.
Leaving a voltage as 0.0V will mean that level is not enabled.
Level-1: 0.0V
Level-2: 0.0V
Level-3: 0.0V
Level-4: 0.0V
Level-5: 0.0V
Memory Start: (Yes/No)
Soft Start: (SLOW/MED/FAST)
Vlow: 0.0V (The voltage where the low voltage warning should kick in.)
Vlow Warning Type: (Pulsing/Dimming/Shutdown Output & Flash PWMA Output)(PWM Duty % when on)
Vlow voltage based shutdown: Percent of Vlow (94%)(Enabled/Disabled)
Vlow timed shutdown: Seconds before shutdown (30 Seconds)(Enabled/Disabled)
Vlow Latch: (Enable/Disable)
Over Temp Warning Type: (Dimming/Shutdown Output & Flash PWMB Output)(PWM Duty % when on)
Relay Disconnect: (Enable/Disable)

Note: You cannot combine the Relay Disconnect option with the PWM A/B options for Low Voltage and Temperature warnings.
Last edited:


Flashlight Enthusiast
Aug 30, 2006
Boston, MA, USA
Pre-orders and payments made:
LuxLuthor: 2 (paid)
Starlight: 3 (paid)
Data: 2 (paid)
petrev: 1 (paid)
Smopoim86: 1 (paid)
BVH: 2 (paid)
2filthy3: 2 (paid)

Confirmation (no payment yet):
Last edited:


May 25, 2002
Confirm me for 3. I will edit this post later in the year with specifics. I assume you want paypal now. If you say yes, I will send it asap.


Flashlight Enthusiast
Aug 30, 2006
Boston, MA, USA
Confirm me for 3. I will edit this post later in the year with specifics. I assume you want paypal now. If you say yes, I will send it asap.
Yes. PayPal now to get the pre-order pricing @ $100 each.
In any case, I'll be contacting all pre-order customers for confirmation of their configuration settings.
Thanks, Starlight.


Flashlight Enthusiast
Aug 30, 2006
Boston, MA, USA
Update to payment details
I just changed the PayPal payment info to include their 3% fee for credit card payments.
Those who have already paid, are fine as you are. It was my oversight. Sorry for the late change.


Flashlight Enthusiast
Jun 12, 2005
SW England
Hi Jimmy

Will update you with specs when I can decide them ! ! !




Apr 2, 2008
Knoxville, TN
I'll be good for one since I committed to it. I'm trying to figure out what I'm going to use it for to decide the settings. I instaflashed all my big bulbs...



Flashlight Enthusiast
Aug 30, 2006
Boston, MA, USA
Many parts have already shipped. Still waiting on a few on back order. The onboard regulator that I was going to have to wait until January for has already shipped. But have to wait a few more weeks for the FETs. I should have the majority of the parts next week or the week after.