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Dec 30, 2010, 10:43 AM
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Cougar429's Avatar
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Help!

IMAX B6 Schematic


This may have been requested and posted before, but no luck locating one.

I'm being sent one of these gems for the cost of shipping and have taken the risk of ordering one of bennetje's resistor upgrade kits, as well. The reason for the gift in the first place is the fact the previous owner "Let the Magic Smoke out of the box". He is unable to identify which component it is and there is the good likelyhood whatever info may have been printed on or near the component is now ash.

I was hoping someone would have a schematic or component ID info to be able to at least make some attempt at repair. I like to tinker.
Last edited by Cougar429; Dec 30, 2010 at 12:36 PM.
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Dec 30, 2010, 01:12 PM
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MoFl's Avatar
I found the attached schematics some time ago, which seem to correspond with one of the multiple B6 clones.

Unfortunately, I don't remember where I found them, so I can't give more details (and the appropriate credit to the author, I hope he doesn't mind).

P.S: Good news for this charger's owners: In the last posts of this thread, you can read the FW has been hacked, so the calibration menu can be unlocked.

EDIT: The schematics come from this Russian forum, and were referred at RCGroups by MartStonia in this post
Last edited by MoFl; Jan 14, 2011 at 06:45 AM. Reason: Links to source of info
Dec 30, 2010, 02:50 PM
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Cougar429's Avatar
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Thanks. I will have to compare once I open up the unit. Hopefully I will be able to identify what was fried and find a replacement.

I read some of that thread and saw the warning about what occurs when you unlock and make a change. If it's repairable I will compare the lab PS reading to what I see on the screen.
Jan 16, 2011, 12:25 PM
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SteveM732's Avatar
Sorry, wring thread. Glad somebody out there is sharing schematics though. I've done them for the FMA 4s and Multi4.
Jan 06, 2015, 02:45 PM
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Piojo's Avatar
Thanks for the files!

Btw, somebody knows if exists new versions of this files?


best regards,
Oct 11, 2017, 08:12 AM
Registered User
Hi guys, where are the B6 schematics?
Oct 12, 2017, 12:22 AM
Frankenstein recycled packs
rampman's Avatar
Quote:
Originally Posted by Herdt
Hi guys, where are the B6 schematics?
Post #4

Rick
Aug 25, 2018, 11:28 AM
Registered User
Has anyone ever seen a parts layout for the B6? Someone assigned component designators to each part, which would be a lot more helpful if there was a component placement drawing.

How about a block diagram? Something that would describe what each sub-circuit does what.... such as:
(these are educated guesses... anybody have better info?)

a) DA3:1, DA3:2, VT10, VT12, VT14, VT16
All of this circuit is the Charge Voltage Supply and Charge Current Regulation. The design is such that it will act as either a “Buck” regulator (step-down), or “Boost” regulator (step-up), to supply Voltage/Current to charge the battery whether the DC Supply Input voltage is too low, just right, or too high. This Voltage is sampled by the micro as "BATT+" through the resistor divider R64, R65, R66, R67 into input “ADC0”.

b) DA2:2, VT9
The MOSFET VT9 connects "BATT-" to GND through R53/R54 current sense resistors (0.05 Ohm total) for the purpose of Charge Current measurement. VT9 is operates only in ON/OFF switched mode (not linear) and is "ON" any time a function is selected, even if it's not yet running.

c) DA2:1
Multiply voltage across R53/R54 current sense resistors by 6.667 to feed to ADC input of micro, represents Battery Current once a discharge cycle is running. At 0.05 Ohms sense resistor, this gives 50mV drop at 1 Amp discharge current, which is then multiplied by 6.667 resulting in 333.33mV at ADC3 at 1 Amp.

d) DA1:1, DA1:2, VT7, R50
Battery Discharge Current regulation. DA1:2 drives VT7 (in linear mode), Charge Current is sensed through R50 (0.5 Ohm) which is sampled, amplified by DA1:1 by 2x, then feed to micro ADC2 and used as negative feedback loop for DA1:2. At 1 Amp of discharge current, there would be 0.5V across R50, which is doubled to 1.0V and fed to the micro.

e) DD1 (74HC4051) = Analog 8:1 switch, selects between each battery balance connection inputs (and Temperature sensor) to feed to analog input "ADC6" of the micro. This gives the micro more Analog ADC Inputs by selecting them one at a time under control of the binary selection bits "S0, S1, S2" from the micro. (it's a digital version of an 8-position rotary selector switch)

f) VD7 (TL431) is the ADC Voltage Reference, which is 2.495V. This results in the 10-bit ADC having 2.4365mV resolution.


...anyone else?
Last edited by robotom; Aug 25, 2018 at 08:02 PM. Reason: more in-depth, & some corrections
Mar 17, 2019, 02:46 PM
Registered User
HI!
Thanks for that explanation. It already show very much.

I have a genuine Imax B6 and after some use and i don't know when, it blows 40p06 mosfet and i confirmed that after the charger blows some of my batterys because input supply voltage was always at the output pins when i start charging any mode. after that i disassembled imax and saw that mosfet is shorted. I replaced it with a 50p06 and the problem is the same. Only if i take it off, it looks like the imax is working fine. Could someone tell for what is that 40p06 mosfet and why i still have the problem after replace the bad part? regards!
Mar 17, 2019, 05:28 PM
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Cougar429's Avatar
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Holy Crap! This thread is 9 years old and still alive?
Mar 17, 2019, 07:59 PM
Registered User
yes and that didn't help to solve the problem.

But i'm here again to tell the solution for my problem that i finally found. Besides the shorted P Mosfet, it was also a 10R resistor and PNP sot32 transistor shorted and after that my IMAX B6 is working again!

In the photos you can also see a bonus to change FAN voltage to 5V. Mine was bad and 15V fan i cant find anywhere. Now with 5V supply to FAN you can use many FAN'S

Hope this can help most of you!
Mar 18, 2019, 10:26 AM
Quadaholic
--Oz--'s Avatar
Quote:
Originally Posted by zinom
yes and that didn't help to solve the problem.

But i'm here again to tell the solution for my problem that i finally found. Besides the shorted P Mosfet, it was also a 10R resistor and PNP sot32 transistor shorted and after that my IMAX B6 is working again!

In the photos you can also see a bonus to change FAN voltage to 5V. Mine was bad and 15V fan i cant find anywhere. Now with 5V supply to FAN you can use many FAN'S

Hope this can help most of you!
Hi, Can you post the full schematic and without mark ups (no yellow highlights) please.
Mar 18, 2019, 10:44 AM
Registered User
Hi. That schematic it's what I have, I've found here or in other forum and for the genuine imax I think is the more reliable schematic. With that piece of schematic I did solve my problem
Mar 26, 2019, 11:14 AM
Quadaholic
--Oz--'s Avatar
Deleted, duplicate do to rgc lagging internet connection.
Last edited by --Oz--; Mar 26, 2019 at 07:44 PM.
Mar 26, 2019, 11:20 AM
Quadaholic
--Oz--'s Avatar
Quote:
Originally Posted by robotom
Has anyone ever seen a parts layout for the B6? Someone assigned component designators to each part, which would be a lot more helpful if there was a component placement drawing.

How about a block diagram? Something that would describe what each sub-circuit does what.... such as:
(these are educated guesses... anybody have better info?)

a) DA3:1, DA3:2, VT10, VT12, VT14, VT16
All of this circuit is the Charge Voltage Supply and Charge Current Regulation. The design is such that it will act as either a “Buck” regulator (step-down), or “Boost” regulator (step-up), to supply Voltage/Current to charge the battery whether the DC Supply Input voltage is too low, just right, or too high. This Voltage is sampled by the micro as "BATT+" through the resistor divider R64, R65, R66, R67 into input “ADC0”.

b) DA2:2, VT9
The MOSFET VT9 connects "BATT-" to GND through R53/R54 current sense resistors (0.05 Ohm total) for the purpose of Charge Current measurement. VT9 is operates only in ON/OFF switched mode (not linear) and is "ON" any time a function is selected, even if it's not yet running.

c) DA2:1
Multiply voltage across R53/R54 current sense resistors by 6.667 to feed to ADC input of micro, represents Battery Current once a discharge cycle is running. At 0.05 Ohms sense resistor, this gives 50mV drop at 1 Amp discharge current, which is then multiplied by 6.667 resulting in 333.33mV at ADC3 at 1 Amp.

d) DA1:1, DA1:2, VT7, R50
Battery Discharge Current regulation. DA1:2 drives VT7 (in linear mode), Charge Current is sensed through R50 (0.5 Ohm) which is sampled, amplified by DA1:1 by 2x, then feed to micro ADC2 and used as negative feedback loop for DA1:2. At 1 Amp of discharge current, there would be 0.5V across R50, which is doubled to 1.0V and fed to the micro.

e) DD1 (74HC4051) = Analog 8:1 switch, selects between each battery balance connection inputs (and Temperature sensor) to feed to analog input "ADC6" of the micro. This gives the micro more Analog ADC Inputs by selecting them one at a time under control of the binary selection bits "S0, S1, S2" from the micro. (it's a digital version of an 8-position rotary selector switch)

f) VD7 (TL431) is the ADC Voltage Reference, which is 2.495V. This results in the 10-bit ADC having 2.4365mV resolution.


...anyone else?
To add to your excellent post:

The LM324 (quad op-amp) DA6 1 to 4, its function is to level shift and divide by two each battery cell voltage (cell number 3 through 6).
Cells 1 and 2 are divided down by simple voltage dividers.
Cell#1 R60, R61, R62, R63 for a divide by 2 (0.5) ratio and
Cell#2 R71, R72, R73, R74 for a divide by 0.255 ratio.

When the output voltage of each LM324 output get to the correct level (referenced to firmware calibration levels), the micro then turns on the corresponding balance circuit transistor (VT17, VT18, VT19, VT20, VT21, VT22. This bleeds the charge current around the cell thats at 4.20V (full charged for LiPo cells). When the first cell gets to 4.20V, then the main charge current is reduced to the capability of the balance circuit, in the iMAX B6 it's 0.3A.

Note: On the iMax B8, there is 2 LM324 IC's, so all 8 cells use the op-amp scaling/dividing method.


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