Help about minipro

[HKT]

I just modded my LedLenser David 15(1AA) with Minipro (adjustable) with Seoul P4.

However, it doesn't bright as expected.

I got minipro from my friend , it is adjustable with the switch near IC.

Sorry for no picture of Minipro (adjustable) board.
I removed this switch out after talking with my friend.
But I don't sure the correct way to do.
I've tried to solder the board under the switch (3 points of switch pin) togeter , it does not work.

After remove solder from that 3 points and connect ground to Pin2, it works but not bright as expected.
I measure the current to led with new alkaline cell is only ~110 mA.
Does it normal ?
I wonder it might be Min due to the output.
I don't know that the output after remove is Min or Max.
If it is min , how to be max output?

Thanks for all answer.

 

[eebowler]

I don't exactly understand the question but I hope this information helps.

Assuming that the IC is the same as the original MiniProIII, THIS document may be helpful. The original design had pins 1,2,3,4 and 5 all connected to ground (-ve). Pin 2 is the feedback(FB) input and according to the pdf, "To adjust the output voltage, connect a resistive voltage-divider from OUT to FB to GND (Figure 6)". The three connections you mentioned above are therefore FB, ground (GND) and output (OUT).

When these documents refer to OUT, they are talking about +ve output. What you did when you soldered all three contacts together was to connect -ve to +ve.

Assuming that you're leaving the resistor out of the circuit, what you need to do is solder feedback to ground (to get an output of max 5V)and connect your +ve wire from the LED to the third spot which would be output. If by chance you connect FB to the output, the max output voltage would be 3.3V.

I actually can't help you much beyond this point since I've never seen or owned a variable output version of the Minpro and variable resistors are still a mystery to me. :0 Other members would be able to help you here.

For reference, a MiniPro III with one fresh AA cell has an output of a little over 300mA to the LED.

There seems to be another forum and THIS is a link to a discussion about the minipro.

 

[r3d33m3r]

That seems to be a 250 OHM Potenciometer ( variable resistor ) so just try to find out what pin goes where or even better, make a picture of the board so i can see the side that this was mounted on, and i will figure out where to solder a normal resistor so you get max output. If you figure out what goes where the resistor shoud be 250 ( not standard value ) or 220 OHM ( standard value ).

 

[HKT]

eebowler,

I can't post any picture ???

Please see the link here for minipro adjustable type
http://home.mchsi.com/~lambda_lights/news.htm

I decided to ground pin2, refer to the non adjust diagram
http://home.mchsi.com/~lambda_lights/miniprodc.htm

But as I said , output to led is only 110 mA, a bit dimmer than expected.

what's wrong, or is this normal?

who can simply explain me how to make adjustable minipro to same output as non-adjust, would be great.
(I've few experience in electronic terms)

Thanks

 

[HKT]

try to post my work again.

 

[HKT]

Again for adjustable minipro

and for non adjust

 

[HKT]

Looks what I done to my L2T with Seoul.
Significantly brighter than Luxeon T bin.

(all by 1/10s. f2.0 ISO200 Daylight WB)

L2T

L2T Seoul

L2T

L2T Seoul

However , this is T bin left....

I don't have beam shot of Minipro yet.
But for Fenix L2T+Seoul , output shows me something wrong with Minipro....

 

[r3d33m3r]

Nice. As far as can see you've connected the right pins, but it looks like the IC is configured somewhat different, so find a 220 OHM ( that is a red-red-brown ) resistor and connect it betwen the ground and the pin2 and give it a try, if it doesent work try connecting pin7 to ground VIA resistor and if even that doesent work, connect the pin2 to pin7 directly.
Good luck.

 

[HKT]

Nice. As far as can see you've connected the right pins, but it looks like the IC is configured somewhat different, so find a 220 OHM ( that is a red-red-brown ) resistor and connect it betwen the ground and the pin2 and give it a try, if it doesent work try connecting pin7 to ground VIA resistor and if even that doesent work, connect the pin2 to pin7 directly.
Good luck.

r3d33m3r,
connect pin2 to pin7 didn't work, that was my first try.

 

[eebowler]

HKT, yeah, it looks like the connections are sound. (Nice pictures by the way.) Maybe you should remove the connections to the LED and test the voltage with one cell (3.3Voutput) and two cells (5V output) connected to the input. This would determine if the circuit is actualy doing what it's built to do.

If it's working, maybe the foward voltage of the LED is really high resulting in
the 110mA current draw on one cell. Do you have any other LEDs other than seoul to test with? Can you somehow connect two cells to the minopro and measure the output current then?

 

[HKT]

HKT, yeah, it looks like the connections are sound. (Nice pictures by the way.) Maybe you should remove the connections to the LED and test the voltage with one cell (3.3Voutput) and two cells (5V output) connected to the input. This would determine if the circuit is actualy doing what it's built to do.

If it's working, maybe the foward voltage of the LED is really high resulting in
the 110mA current draw on one cell. Do you have any other LEDs other than seoul to test with? Can you somehow connect two cells to the minopro and measure the output current then?

with 2 alkaline is only around 230 mA.

But I don't understand about voltage with no load.
even one or two cell , it shows ~5V output ?????
I don't sure I was wrong or not ...

 

[HKT]

Better to see the beam shot for comparison

First from stock David 15

and from Seoul P4 + Minipro

Seoul seems to be brighter because of huge side spill from McR16.
But looking at center for throw, I can say throw from stock is a little bit brighter or might be same,

Shooting for the long distance, no merit for changing to seoul.

For reference,
I use my digi-camera measure the light at the center.
with same setting (Aperture, iso,...) , the shutter speed reading at center (around 1 foot from the wall) is 1/640s for stock and 1/500s for seoul+minipro.

 

[chimo]

The minipro is a voltage boost converter with a max voltage of 5V. If it's showing 5V with no load, that's good.

The IC for the minipro tries to boost the voltage to the converter's set point (5V or whatever the voltage divider is set for on the adjustable version). However, the IC also limits the input current to approx 1A when it is trying to achieve the output set point.

If you are running on a single NiMH cell, the max power in is: 1A x 1.2V = 1.2W

Let's assume an efficiency of 80%. Power to the emitter will be around 1W.

Let's say that the emitter has a Vf of 3.3V when being driven at a watt. In this case, the emitter current would be about 300mA.

Be careful how you measure current. If you use a high resistance measuring device you could raise the output resistance and the output current will appear less (should be no lower than 200mA for the example above). If you are using a DMM in current mode, use the 10A setting with the leads in series with the emitter.

You could also contact the manufacturer of the minipro, Lambda, with your questions.

 

[HKT]

Thanks, Chimo.

 

[HKT]

just add information,

I heard from my friend that minipro should draw nearly 1 amp from fresh batt.
I measured mine was only 600 mA...
Something wrong sure.....