Vintage Simmons Drums (UK) Users Group

Hi list,

I thought I should change the battery of my latest MTM today. But since 
I was stupid enough not to make notes or take pictures when last time 
doing this I dug out one of the other units to have a look.

No. 114 had it's battery changed by the former owner and as far as I 
remember I copied the work in my other MTM. Apart from the removal of 
the old battery and the insertion of a AA-sized Lithium dito I can only 
see one change: the lifting/removal of resistor 37. I did the same on my 
other MTM and both works well, both functions and memory.

Here's a shot of what can be seen inside no. 114.
http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg

So techs, let me know if this is wrong. Should I lift diode 30 too? 
Anything else? The schematics aren't the best and I'm no master at 
reading it anyway. :)

Happy holidays,
-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

I would just put a diode in series with the + side of the Lithium-cell.

How you do it depends on where you put the Lithium-cell.

WT

----- Original Message ----- 

From: "jesper" <jesper@...>
To: <Simmons_Drums@yahoogroups.com>
Sent: Wednesday, December 28, 2011 10:57 AM
Subject: [Simmons Drums] MTM and change of battery


> Hi list,
> 
> I thought I should change the battery of my latest MTM today. But since 
> I was stupid enough not to make notes or take pictures when last time 
> doing this I dug out one of the other units to have a look.
> 
> No. 114 had it's battery changed by the former owner and as far as I 
> remember I copied the work in my other MTM. Apart from the removal of 
> the old battery and the insertion of a AA-sized Lithium dito I can only 
> see one change: the lifting/removal of resistor 37. I did the same on my 
> other MTM and both works well, both functions and memory.
> 
> Here's a shot of what can be seen inside no. 114.
> http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
> 
> So techs, let me know if this is wrong. Should I lift diode 30 too? 
> Anything else? The schematics aren't the best and I'm no master at 
> reading it anyway. :)
> 
> Happy holidays,
> -- 
> electronically yours, jesper
> 
> - -- --- ---- ----- ---- --- -- -
> www.electronic-obsession.se
> 
> 
> ------------------------------------
> 
> Yahoo! Groups Links
> 
> 
>

I replaced my battery in my sds 9 ,mtm,and mtx the same way i described in the sds 9 descriptions as before no resistors or any thing to be taken out,three 1.2 volt AA batteries equals 3.6 volts which it calls for.they where ni cads as i recall rechargeable from radio shack,and the four AA holder in plastic ,just bypass the fourth battery spot with solder jumper cables ,case is in plstic in case of leakage and used d0uble sided sticky tape to mount to sie walls,and of course positive wire to positive on bord and negative to negative on board .as stated in service guide batteries have to be charged for mtm to work,my mtm  and all worked fine this way,just heard mine might not be trggering due to capacitors failing after all those years.sure would be nice to have readable schematics



________________________________

From: jesper <jesper@...>
To: Simmons_Drums@yahoogroups.com 
Sent: Wednesday, December 28, 2011 1:57 AM
Subject: [Simmons Drums] MTM and change of battery


  
Hi list,

I thought I should change the battery of my latest MTM today. But since 
I was stupid enough not to make notes or take pictures when last time 
doing this I dug out one of the other units to have a look.

No. 114 had it's battery changed by the former owner and as far as I 
remember I copied the work in my other MTM. Apart from the removal of 
the old battery and the insertion of a AA-sized Lithium dito I can only 
see one change: the lifting/removal of resistor 37. I did the same on my 
other MTM and both works well, both functions and memory.

Here's a shot of what can be seen inside no. 114.
http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg

So techs, let me know if this is wrong. Should I lift diode 30 too? 
Anything else? The schematics aren't the best and I'm no master at 
reading it anyway. :)

Happy holidays,
-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se



[Non-text portions of this message have been removed]

Hi WT,

so, basically just between the PCB solder point and the red wire in my 
photo? To block any voltage from reaching the battery? Any critical 
value or would any decent diode do?

thanks,
/j.


WT skrev 2011-12-29 00:50:
> I would just put a diode in series with the + side of the Lithium-cell.
>
> How you do it depends on where you put the Lithium-cell.
>
> WT
>
> ----- Original Message -----
> From: "jesper" <jesper@...
> <mailto:jesper%40electronic-obsession.se>>
> To: <Simmons_Drums@yahoogroups.com <mailto:Simmons_Drums%40yahoogroups.com>>
> Sent: Wednesday, December 28, 2011 10:57 AM
> Subject: [Simmons Drums] MTM and change of battery
>
>  > Hi list,
>  >
>  > I thought I should change the battery of my latest MTM today. But since
>  > I was stupid enough not to make notes or take pictures when last time
>  > doing this I dug out one of the other units to have a look.
>  >
>  > No. 114 had it's battery changed by the former owner and as far as I
>  > remember I copied the work in my other MTM. Apart from the removal of
>  > the old battery and the insertion of a AA-sized Lithium dito I can only
>  > see one change: the lifting/removal of resistor 37. I did the same on my
>  > other MTM and both works well, both functions and memory.
>  >
>  > Here's a shot of what can be seen inside no. 114.
>  > http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
>  >
>  > So techs, let me know if this is wrong. Should I lift diode 30 too?
>  > Anything else? The schematics aren't the best and I'm no master at
>  > reading it anyway. :)
>  >
>  > Happy holidays,
>  > --
>  > electronically yours, jesper
>  >
>  > - -- --- ---- ----- ---- --- -- -
>  > www.electronic-obsession.se
>  >
>  >
>  > ------------------------------------
>  >
>  > Yahoo! Groups Links
>  >
>  >
>  >
>
> 


-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

OK, me again, with insomnia, hence the somewhat slow brain...

I checked the schematics and noted that the two components on the + side 
of the battery is in fact "just" the mentioned resistor (37) and the 
diode (30) already in place.

http://www.electronic-obsession.se/studio/simmons/mtm_battery_circuit.jpg

So I cannot see any need for another diode. Please correct me if I'm 
misinterpreting anything.

/j.


jesper skrev 2011-12-29 05:00:
> Hi WT,
>
> so, basically just between the PCB solder point and the red wire in my
> photo? To block any voltage from reaching the battery? Any critical
> value or would any decent diode do?
>
> thanks,
> /j.
>
>
> WT skrev 2011-12-29 00:50:
>> I would just put a diode in series with the + side of the Lithium-cell.
>>
>> How you do it depends on where you put the Lithium-cell.
>>
>> WT
>>
>> ----- Original Message -----
>> From: "jesper"<jesper@...
>> <mailto:jesper%40electronic-obsession.se>>
>> To:<Simmons_Drums@yahoogroups.com<mailto:Simmons_Drums%40yahoogroups.com>>
>> Sent: Wednesday, December 28, 2011 10:57 AM
>> Subject: [Simmons Drums] MTM and change of battery
>>
>>   >  Hi list,
>>   >
>>   >  I thought I should change the battery of my latest MTM today. But since
>>   >  I was stupid enough not to make notes or take pictures when last time
>>   >  doing this I dug out one of the other units to have a look.
>>   >
>>   >  No. 114 had it's battery changed by the former owner and as far as I
>>   >  remember I copied the work in my other MTM. Apart from the removal of
>>   >  the old battery and the insertion of a AA-sized Lithium dito I can only
>>   >  see one change: the lifting/removal of resistor 37. I did the same on my
>>   >  other MTM and both works well, both functions and memory.
>>   >
>>   >  Here's a shot of what can be seen inside no. 114.
>>   >  http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
>>   >
>>   >  So techs, let me know if this is wrong. Should I lift diode 30 too?
>>   >  Anything else? The schematics aren't the best and I'm no master at
>>   >  reading it anyway. :)
>>   >
>>   >  Happy holidays,
>>   >  --
>>   >  electronically yours, jesper
>>   >
>>   >  - -- --- ---- ----- ---- --- -- -
>>   >  www.electronic-obsession.se
>>   >
>>   >
>>   >  ------------------------------------
>>   >
>>   >  Yahoo! Groups Links
>>   >
>>   >
>>   >
>>
>>
>
>


-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

Brian Horton skrev 2011-12-29 03:29:
> I replaced my battery in my sds 9 ,mtm,and mtx the same way i described
> in the sds 9 descriptions as before no resistors or any thing to be
> taken out,three 1.2 volt AA batteries equals 3.6 volts which it calls
> for.they where ni cads as i recall rechargeable from radio shack,and the
> four AA holder in plastic ,just bypass the fourth battery spot with
> solder jumper cables ,case is in plstic in case of leakage and used
> d0uble sided sticky tape to mount to sie walls,and of course positive
> wire to positive on bord and negative to negative on board .as stated in
> service guide batteries have to be charged for mtm to work,my mtm  and
> all worked fine this way,just heard mine might not be trggering due to
> capacitors failing after all those years.sure would be nice to have
> readable schematics


I know you did, but I wanted to remove the battery from the PCB and 
change into a lithium type to avoid future leakage. Which reminds me to 
check my OSCar... I bet it's time for an upgrade there too.

-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

That diode doesn\ufffdt block the charging voltage. If it did, how would the 
original battery get charged ?

WT

----- Original Message ----- 

From: "jesper" <jesper@...>
To: <Simmons_Drums@yahoogroups.com>
Sent: Thursday, December 29, 2011 5:17 AM
Subject: Re: [Simmons Drums] MTM and change of battery


> OK, me again, with insomnia, hence the somewhat slow brain...
>
> I checked the schematics and noted that the two components on the + side
> of the battery is in fact "just" the mentioned resistor (37) and the
> diode (30) already in place.
>
> http://www.electronic-obsession.se/studio/simmons/mtm_battery_circuit.jpg
>
> So I cannot see any need for another diode. Please correct me if I'm
> misinterpreting anything.
>
> /j.
>
>
> jesper skrev 2011-12-29 05:00:
>> Hi WT,
>>
>> so, basically just between the PCB solder point and the red wire in my
>> photo? To block any voltage from reaching the battery? Any critical
>> value or would any decent diode do?
>>
>> thanks,
>> /j.
>>
>>
>> WT skrev 2011-12-29 00:50:
>>> I would just put a diode in series with the + side of the Lithium-cell.
>>>
>>> How you do it depends on where you put the Lithium-cell.
>>>
>>> WT
>>>
>>> ----- Original Message -----
>>> From: "jesper"<jesper@...
>>> <mailto:jesper%40electronic-obsession.se>>
>>> To:<Simmons_Drums@yahoogroups.com<mailto:Simmons_Drums%40yahoogroups.com>>
>>> Sent: Wednesday, December 28, 2011 10:57 AM
>>> Subject: [Simmons Drums] MTM and change of battery
>>>
>>>   >  Hi list,
>>>   >
>>>   >  I thought I should change the battery of my latest MTM today. But 
>>> since
>>>   >  I was stupid enough not to make notes or take pictures when last 
>>> time
>>>   >  doing this I dug out one of the other units to have a look.
>>>   >
>>>   >  No. 114 had it's battery changed by the former owner and as far as 
>>> I
>>>   >  remember I copied the work in my other MTM. Apart from the removal 
>>> of
>>>   >  the old battery and the insertion of a AA-sized Lithium dito I can 
>>> only
>>>   >  see one change: the lifting/removal of resistor 37. I did the same 
>>> on my
>>>   >  other MTM and both works well, both functions and memory.
>>>   >
>>>   >  Here's a shot of what can be seen inside no. 114.
>>>   > 
>>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
>>>   >
>>>   >  So techs, let me know if this is wrong. Should I lift diode 30 too?
>>>   >  Anything else? The schematics aren't the best and I'm no master at
>>>   >  reading it anyway. :)
>>>   >
>>>   >  Happy holidays,
>>>   >  --
>>>   >  electronically yours, jesper
>>>   >
>>>   >  - -- --- ---- ----- ---- --- -- -
>>>   >  www.electronic-obsession.se
>>>   >
>>>   >
>>>   >  ------------------------------------
>>>   >
>>>   >  Yahoo! Groups Links
>>>   >
>>>   >
>>>   >
>>>
>>>
>>
>>
>
>
> -- 
> electronically yours, jesper
>
> - -- --- ---- ----- ---- --- -- -
> www.electronic-obsession.se
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

True... stupid me. OK, a new diode it is and the same for both of the 
others.

thanks,

/j.


  WT skrev 2011-12-29 09:55:
> That diode doesn´t block the charging voltage. If it did, how would the
> original battery get charged ?
>
> WT
>
> ----- Original Message -----
> From: "jesper"<jesper@electronic-obsession.se>
> To:<Simmons_Drums@yahoogroups.com>
> Sent: Thursday, December 29, 2011 5:17 AM
> Subject: Re: [Simmons Drums] MTM and change of battery
>
>
>> OK, me again, with insomnia, hence the somewhat slow brain...
>>
>> I checked the schematics and noted that the two components on the + side
>> of the battery is in fact "just" the mentioned resistor (37) and the
>> diode (30) already in place.
>>
>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_circuit.jpg
>>
>> So I cannot see any need for another diode. Please correct me if I'm
>> misinterpreting anything.
>>
>> /j.
>>
>>
>> jesper skrev 2011-12-29 05:00:
>>> Hi WT,
>>>
>>> so, basically just between the PCB solder point and the red wire in my
>>> photo? To block any voltage from reaching the battery? Any critical
>>> value or would any decent diode do?
>>>
>>> thanks,
>>> /j.
>>>
>>>
>>> WT skrev 2011-12-29 00:50:
>>>> I would just put a diode in series with the + side of the Lithium-cell.
>>>>
>>>> How you do it depends on where you put the Lithium-cell.
>>>>
>>>> WT
>>>>
>>>> ----- Original Message -----
>>>> From: "jesper"<jesper@...
>>>> <mailto:jesper%40electronic-obsession.se>>
>>>> To:<Simmons_Drums@yahoogroups.com<mailto:Simmons_Drums%40yahoogroups.com>>
>>>> Sent: Wednesday, December 28, 2011 10:57 AM
>>>> Subject: [Simmons Drums] MTM and change of battery
>>>>
>>>>    >   Hi list,
>>>>    >
>>>>    >   I thought I should change the battery of my latest MTM today. But
>>>> since
>>>>    >   I was stupid enough not to make notes or take pictures when last
>>>> time
>>>>    >   doing this I dug out one of the other units to have a look.
>>>>    >
>>>>    >   No. 114 had it's battery changed by the former owner and as far as
>>>> I
>>>>    >   remember I copied the work in my other MTM. Apart from the removal
>>>> of
>>>>    >   the old battery and the insertion of a AA-sized Lithium dito I can
>>>> only
>>>>    >   see one change: the lifting/removal of resistor 37. I did the same
>>>> on my
>>>>    >   other MTM and both works well, both functions and memory.
>>>>    >
>>>>    >   Here's a shot of what can be seen inside no. 114.
>>>>    >
>>>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
>>>>    >
>>>>    >   So techs, let me know if this is wrong. Should I lift diode 30 too?
>>>>    >   Anything else? The schematics aren't the best and I'm no master at
>>>>    >   reading it anyway. :)
>>>>    >
>>>>    >   Happy holidays,
>>>>    >   --
>>>>    >   electronically yours, jesper
>>>>    >
>>>>    >   - -- --- ---- ----- ---- --- -- -
>>>>    >   www.electronic-obsession.se
>>>>    >
>>>>    >
>>>>    >   ------------------------------------
>>>>    >
>>>>    >   Yahoo! Groups Links
>>>>    >
>>>>    >
>>>>    >
>>>>
>>>>
>>>
>>>
>>
>>
>> --
>> electronically yours, jesper
>>
>> - -- --- ---- ----- ---- --- -- -
>> www.electronic-obsession.se
>>
>>
>> ------------------------------------
>>
>> Yahoo! Groups Links
>>
>>
>>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>


-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

But, what's it for then? I thought the original charge came over the 
resistor.

/j.

WT skrev 2011-12-29 09:55:
> That diode doesn´t block the charging voltage. If it did, how would the
> original battery get charged ?
>
> WT
>
> ----- Original Message -----
> From: "jesper"<jesper@electronic-obsession.se>
> To:<Simmons_Drums@yahoogroups.com>
> Sent: Thursday, December 29, 2011 5:17 AM
> Subject: Re: [Simmons Drums] MTM and change of battery
>
>
>> OK, me again, with insomnia, hence the somewhat slow brain...
>>
>> I checked the schematics and noted that the two components on the + side
>> of the battery is in fact "just" the mentioned resistor (37) and the
>> diode (30) already in place.
>>
>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_circuit.jpg
>>
>> So I cannot see any need for another diode. Please correct me if I'm
>> misinterpreting anything.
>>
>> /j.
>>
>>
>> jesper skrev 2011-12-29 05:00:
>>> Hi WT,
>>>
>>> so, basically just between the PCB solder point and the red wire in my
>>> photo? To block any voltage from reaching the battery? Any critical
>>> value or would any decent diode do?
>>>
>>> thanks,
>>> /j.
>>>
>>>
>>> WT skrev 2011-12-29 00:50:
>>>> I would just put a diode in series with the + side of the Lithium-cell.
>>>>
>>>> How you do it depends on where you put the Lithium-cell.
>>>>
>>>> WT
>>>>
>>>> ----- Original Message -----
>>>> From: "jesper"<jesper@electronic-obsession.se
>>>> <mailto:jesper%40electronic-obsession.se>>
>>>> To:<Simmons_Drums@yahoogroups.com<mailto:Simmons_Drums%40yahoogroups.com>>
>>>> Sent: Wednesday, December 28, 2011 10:57 AM
>>>> Subject: [Simmons Drums] MTM and change of battery
>>>>
>>>>    >   Hi list,
>>>>    >
>>>>    >   I thought I should change the battery of my latest MTM today. But
>>>> since
>>>>    >   I was stupid enough not to make notes or take pictures when last
>>>> time
>>>>    >   doing this I dug out one of the other units to have a look.
>>>>    >
>>>>    >   No. 114 had it's battery changed by the former owner and as far as
>>>> I
>>>>    >   remember I copied the work in my other MTM. Apart from the removal
>>>> of
>>>>    >   the old battery and the insertion of a AA-sized Lithium dito I can
>>>> only
>>>>    >   see one change: the lifting/removal of resistor 37. I did the same
>>>> on my
>>>>    >   other MTM and both works well, both functions and memory.
>>>>    >
>>>>    >   Here's a shot of what can be seen inside no. 114.
>>>>    >
>>>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
>>>>    >
>>>>    >   So techs, let me know if this is wrong. Should I lift diode 30 too?
>>>>    >   Anything else? The schematics aren't the best and I'm no master at
>>>>    >   reading it anyway. :)
>>>>    >
>>>>    >   Happy holidays,
>>>>    >   --
>>>>    >   electronically yours, jesper
>>>>    >
>>>>    >   - -- --- ---- ----- ---- --- -- -
>>>>    >   www.electronic-obsession.se
>>>>    >
>>>>    >
>>>>    >   ------------------------------------
>>>>    >
>>>>    >   Yahoo! Groups Links
>>>>    >
>>>>    >
>>>>    >
>>>>
>>>>
>>>
>>>
>>
>>
>> --
>> electronically yours, jesper
>>
>> - -- --- ---- ----- ---- --- -- -
>> www.electronic-obsession.se
>>
>>
>> ------------------------------------
>>
>> Yahoo! Groups Links
>>
>>
>>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>


-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se

Ah, didn\ufffdt look to much on the schematic.

You mean if you remove the resistor that the diode will block the charging 
voltage ? Possibly. I don\ufffdt know what type of diode it is.

Remove the resistor and measure the voltage before and after the diode.

There should be no voltage after the diode.

WT

----- Original Message ----- 
From: "jesper" <jesper@...>
To: <Simmons_Drums@yahoogroups.com>
Sent: Thursday, December 29, 2011 1:40 PM
Subject: Re: [Simmons Drums] MTM and change of battery


But, what's it for then? I thought the original charge came over the
resistor.

/j.

WT skrev 2011-12-29 09:55:
> That diode doesn\ufffdt block the charging voltage. If it did, how would the
> original battery get charged ?
>
> WT
>
> ----- Original Message -----
> From: "jesper"<jesper@...>
> To:<Simmons_Drums@yahoogroups.com>
> Sent: Thursday, December 29, 2011 5:17 AM
> Subject: Re: [Simmons Drums] MTM and change of battery
>
>
>> OK, me again, with insomnia, hence the somewhat slow brain...
>>
>> I checked the schematics and noted that the two components on the + side
>> of the battery is in fact "just" the mentioned resistor (37) and the
>> diode (30) already in place.
>>
>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_circuit.jpg
>>
>> So I cannot see any need for another diode. Please correct me if I'm
>> misinterpreting anything.
>>
>> /j.
>>
>>
>> jesper skrev 2011-12-29 05:00:
>>> Hi WT,
>>>
>>> so, basically just between the PCB solder point and the red wire in my
>>> photo? To block any voltage from reaching the battery? Any critical
>>> value or would any decent diode do?
>>>
>>> thanks,
>>> /j.
>>>
>>>
>>> WT skrev 2011-12-29 00:50:
>>>> I would just put a diode in series with the + side of the Lithium-cell.
>>>>
>>>> How you do it depends on where you put the Lithium-cell.
>>>>
>>>> WT
>>>>
>>>> ----- Original Message -----
>>>> From: "jesper"<jesper@...
>>>> <mailto:jesper%40electronic-obsession.se>>
>>>> To:<Simmons_Drums@yahoogroups.com<mailto:Simmons_Drums%40yahoogroups.com>>
>>>> Sent: Wednesday, December 28, 2011 10:57 AM
>>>> Subject: [Simmons Drums] MTM and change of battery
>>>>
>>>>    >   Hi list,
>>>>    >
>>>>    >   I thought I should change the battery of my latest MTM today. 
>>>> But
>>>> since
>>>>    >   I was stupid enough not to make notes or take pictures when last
>>>> time
>>>>    >   doing this I dug out one of the other units to have a look.
>>>>    >
>>>>    >   No. 114 had it's battery changed by the former owner and as far 
>>>> as
>>>> I
>>>>    >   remember I copied the work in my other MTM. Apart from the 
>>>> removal
>>>> of
>>>>    >   the old battery and the insertion of a AA-sized Lithium dito I 
>>>> can
>>>> only
>>>>    >   see one change: the lifting/removal of resistor 37. I did the 
>>>> same
>>>> on my
>>>>    >   other MTM and both works well, both functions and memory.
>>>>    >
>>>>    >   Here's a shot of what can be seen inside no. 114.
>>>>    >
>>>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
>>>>    >
>>>>    >   So techs, let me know if this is wrong. Should I lift diode 30 
>>>> too?
>>>>    >   Anything else? The schematics aren't the best and I'm no master 
>>>> at
>>>>    >   reading it anyway. :)
>>>>    >
>>>>    >   Happy holidays,
>>>>    >   --
>>>>    >   electronically yours, jesper
>>>>    >
>>>>    >   - -- --- ---- ----- ---- --- -- -
>>>>    >   www.electronic-obsession.se
>>>>    >
>>>>    >
>>>>    >   ------------------------------------
>>>>    >
>>>>    >   Yahoo! Groups Links
>>>>    >
>>>>    >
>>>>    >
>>>>
>>>>
>>>
>>>
>>
>>
>> --
>> electronically yours, jesper
>>
>> - -- --- ---- ----- ---- --- -- -
>> www.electronic-obsession.se
>>
>>
>> ------------------------------------
>>
>> Yahoo! Groups Links
>>
>>
>>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>


-- 
electronically yours, jesper

- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se



------------------------------------

Yahoo! Groups Links

Hi list,

Battery replaced, the diode in place blocks out just about everything 
(ca 4,4 volts) leaving circa 10 mV bleed through. I added another diode 
which took it down to 3 mV. Some of this might be leakage in a lousy 
multimeter etc but I think this is sufficient enough to count as not 
re-charging. :)

The original battery in MTM 744 is now removed. Nothing had leaked 
outside the plastic container which is a relief. When opening the 
container there were plenty of leakage visible though. *yuck*

Feel free to use this picture as guidance. Red wire goes to + and black 
to - on the new battery which is placed _beside_ the PCB, not on it. 
Remember to lift/remove resistor 37. Additional diode might be good but 
is probably not crucial.

http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg

(just 24 hours left to SDS-2012 (Simmons Drum Season 2012). :D

-- 
electronically yours, jesper

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WT skrev 2011-12-29 13:59:

> Ah, didn´t look to much on the schematic.
>
> You mean if you remove the resistor that the diode will block the charging
> voltage ? Possibly. I don´t know what type of diode it is.
>
> Remove the resistor and measure the voltage before and after the diode.
>
> There should be no voltage after the diode.
>
> WT
>
> ----- Original Message -----
> From: "jesper"<jesper@...>
> To:<Simmons_Drums@yahoogroups.com>
> Sent: Thursday, December 29, 2011 1:40 PM
> Subject: Re: [Simmons Drums] MTM and change of battery
>
>
> But, what's it for then? I thought the original charge came over the
> resistor.
>
> /j.
>
> WT skrev 2011-12-29 09:55:
>> That diode doesn´t block the charging voltage. If it did, how would the
>> original battery get charged ?
>>
>> WT
>>
>> ----- Original Message -----
>> From: "jesper"<jesper@electronic-obsession.se>
>> To:<Simmons_Drums@yahoogroups.com>
>> Sent: Thursday, December 29, 2011 5:17 AM
>> Subject: Re: [Simmons Drums] MTM and change of battery
>>
>>
>>> OK, me again, with insomnia, hence the somewhat slow brain...
>>>
>>> I checked the schematics and noted that the two components on the + side
>>> of the battery is in fact "just" the mentioned resistor (37) and the
>>> diode (30) already in place.
>>>
>>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_circuit.jpg
>>>
>>> So I cannot see any need for another diode. Please correct me if I'm
>>> misinterpreting anything.
>>>
>>> /j.
>>>
>>>
>>> jesper skrev 2011-12-29 05:00:
>>>> Hi WT,
>>>>
>>>> so, basically just between the PCB solder point and the red wire in my
>>>> photo? To block any voltage from reaching the battery? Any critical
>>>> value or would any decent diode do?
>>>>
>>>> thanks,
>>>> /j.
>>>>
>>>>
>>>> WT skrev 2011-12-29 00:50:
>>>>> I would just put a diode in series with the + side of the Lithium-cell.
>>>>>
>>>>> How you do it depends on where you put the Lithium-cell.
>>>>>
>>>>> WT
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "jesper"<jesper@...
>>>>> <mailto:jesper%40electronic-obsession.se>>
>>>>> To:<Simmons_Drums@yahoogroups.com<mailto:Simmons_Drums%40yahoogroups.com>>
>>>>> Sent: Wednesday, December 28, 2011 10:57 AM
>>>>> Subject: [Simmons Drums] MTM and change of battery
>>>>>
>>>>>     >    Hi list,
>>>>>     >
>>>>>     >    I thought I should change the battery of my latest MTM today.
>>>>> But
>>>>> since
>>>>>     >    I was stupid enough not to make notes or take pictures when last
>>>>> time
>>>>>     >    doing this I dug out one of the other units to have a look.
>>>>>     >
>>>>>     >    No. 114 had it's battery changed by the former owner and as far
>>>>> as
>>>>> I
>>>>>     >    remember I copied the work in my other MTM. Apart from the
>>>>> removal
>>>>> of
>>>>>     >    the old battery and the insertion of a AA-sized Lithium dito I
>>>>> can
>>>>> only
>>>>>     >    see one change: the lifting/removal of resistor 37. I did the
>>>>> same
>>>>> on my
>>>>>     >    other MTM and both works well, both functions and memory.
>>>>>     >
>>>>>     >    Here's a shot of what can be seen inside no. 114.
>>>>>     >
>>>>> http://www.electronic-obsession.se/studio/simmons/mtm_battery_mod.jpg
>>>>>     >
>>>>>     >    So techs, let me know if this is wrong. Should I lift diode 30
>>>>> too?
>>>>>     >    Anything else? The schematics aren't the best and I'm no master
>>>>> at
>>>>>     >    reading it anyway. :)
>>>>>     >
>>>>>     >    Happy holidays,
>>>>>     >    --
>>>>>     >    electronically yours, jesper
>>>>>     >
>>>>>     >    - -- --- ---- ----- ---- --- -- -
>>>>>     >    www.electronic-obsession.se
>>>>>     >
>>>>>     >
>>>>>     >    ------------------------------------
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>>>>>     >    Yahoo! Groups Links
>>>>>     >
>>>>>     >
>>>>>     >
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> electronically yours, jesper
>>>
>>> - -- --- ---- ----- ---- --- -- -
>>> www.electronic-obsession.se
>>>
>>>
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>>>
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>>>
>>>
>>>
>>
>>
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