Vintage Simmons Drums (UK) Users Group

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
>>>   >
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>>>
>>>
>>
>>
>
>
> -- 
> electronically yours, jesper
>
> - -- --- ---- ----- ---- --- -- -
> www.electronic-obsession.se
>
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