ArcMania MicroConverter & ArcAAA Converter Data

[chimo]

Here is some test data for the ArcMania 50mA 10mm driver.

Current measuring was done with:
a 0.1 ohm (1%) resistor on Vin (Vin was measured at the board)
a 0.05 ohm (1%) resistor in line with a Nichia DS LED on the output

Turn on transition was around 0.77V.
I checked the slight dip at 1.5V twice to be sure.
Efficiency is not too bad for a 1.5V boost driver 60-70%.
Current regulation is not bad either between 1-1.7Volts in.

Iin(mA)	Vin(V)	Pin(mW)	Iout(mA)	Vout(V)	Pout(mW)	Eff(%)
84.5	1.7	143.7	29.2		2.982	87.1		60.6
110.8	1.6	177.3	39.2		3.075	120.5		68.0
99.2	1.5	148.8	30.2		2.993	90.4		60.7
124.3	1.4	174.0	38.2		3.064	117.0		67.3
152.7	1.3	198.5	45.6		3.13	142.7		71.9
149.6	1.2	179.5	40.4		3.085	124.6		69.4
166.3	1.1	182.9	38.8		3.078	119.4		65.3
180.1	1	180.1	36		3.054	109.9		61.0
126.3	0.9	113.7	19		2.886	54.8		48.2
46.2	0.8	37.0	1.6		2.603	4.2		11.3

Note that this chart has two Y axis. (Power on the left and Efficiency / Output Current on the right)

Here is the same profile for the ArcAAA.
Same LED and sense resistors used.

ArcAAA Converter						
						
Vin(V)	Iin(mA)	Pin(mW)	Vout(V)	Iout(mA)	Pout(mW)	Efficiency (%)
1.7	252	428.4	3.385	81		274.2		64.0
1.6	251	401.6	3.296	72.2		238.0		59.3
1.5	252	378.0	3.251	66.2		215.2		56.9
1.4	256	358.4	3.205	59		189.1		52.8
1.3	259	336.7	3.148	51.6		162.4		48.2
1.2	211	253.2	3.089	43.8		135.3		53.4
1.1	158	173.8	3.015	34.8		104.9		60.4
1	120	120.0	2.933	25.2		73.9		61.6
0.9	104	93.6	2.886	20.2		58.3		62.3
0.8	90	72.0	2.832	15.4		43.6		60.6
0.7	75	52.5	2.779	11.4		31.7		60.3
0.6	60	36.0	2.727	8		21.8		60.6
0.5	49	24.5	2.683	5.2		14.0		56.9
0.4	37	14.8	2.637	3.4		9.0		60.6
0.3	27	8.1	2.596	1.8		4.7		57.7
0.2	17	3.4	2.55	0.8		2.0		60.0
0.1	8	0.8	2.475	0.2		0.5		61.9

Here is comparison of the two.

Observations:
I have graphed similar portions of the Vin range for each of these converters.

They both require around the same trigger voltage to turn on (~0.8V), however, the ArcAAA converter has a bootstrap configuration. Once it is running, it will continue run down to a Vin of <0.1V. The ArcMania MC will turn off between 0.7-0.8V.

So what? - you may ask? If you are running secondary batteries (NiMH) and want over-discharge protection for the cell, the ArcMania converter is a better option. If you are running primary cells (Alkaline/L92), the ArcAAA converter will drain the battery completely.

Effective battery voltage ranges (consider this when examining the graphs):
Alkaline: 0.8-1.5V
NiMH: 0.9-1.3V
L92 (Lithium): ~1.1-1.6V

Efficiency Comparison

Output (LED) Current Comparison.

 

[TMorita]

Re: ArcMania Micro Converter profile

Is this available already? and if so, from where?

Toshi

 

[chimo]

Re: ArcMania Micro Converter profile

Is this available already? and if so, from where?

Toshi

Send ArcMania a PM. He has them in a variety of currents (set by the inductor value, I believe).

 

[chimo]

I have added a similar plot for an ArcAAA converter in the first post and modified the title to reflect the changes.

 

[koala]

Hi Chimo,
your data reminds me of Newbie. Good job there, thanks.

Have you tried other inductors?

 

[chimo]

Hi Chimo,
your data reminds me of Newbie. Good job there, thanks.

Have you tried other inductors?

Thanks, I miss Newbie's technical posts. Mine don't come near the level of detail (and effort) that he put in.

These are stock converters - I haven't changed any of the components.

Paul