Dumb question. i'm a newbie but need help!

Kermit2

Joined Feb 5, 2010
4,163
The preamp has a 5.5 volt max VCC and I believe the datasheet said 2.4 volt minimum.
If your power amp needs higher voltage you will have to add a 5 volt regulator.
As for connection you simply add two wires to the preamp output and plug both into your stereo power amp.
 

wayneh

Joined Sep 9, 2010
16,162
I need help For wiring yhis two circuits with the same battery.
What battery would you like to use? 3 AAs in series would work, 4 if you use rechargeable Ni-cads. A single Li-ion battery (3.7V nominal) would probably work, but as it discharges your power amp might not be happy (data sheet says 3.6V minimum). A sealed lead-acid (SLA) at 4.5V would work. There are lots of options since your two devices overlap in the 3.6-5V range.
 

wayneh

Joined Sep 9, 2010
16,162
Two li-ion in parallel at 3.7V? Is that a commercial pack or your own arrangement? The cells need to be (and will be) closely matched in a commercial battery pack. Otherwise it's not such a good idea to put them in parallel.

You may not be able to use the full capacity of the Li-ion batteries, since they have ~40% capacity remaining when they hit the minimum needed by your power amp.

And your drawing seems correct for the power. Can't comment on the mic but it looks reasonable.
 

Thread Starter

paldep

Joined Mar 3, 2016
41
I need a battery such as old Nokia bl 5c. I saw a Project that use pam8403 Board with the same battery. I dont know if i can Connect two batteries of the same size. I dont know if it's safe.

I dont know in How much time it will discharge.
 
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Dodgydave

Joined Jun 22, 2012
8,681
Discharge time depends on how much current is drawn from the battery, a Nokia battey is approx 850maH, so you can use any combination of current that will give you 850maH

Example 1mA for 850hours
10mA for 85hours
OR. 100mA for 8.5hours
 

Dodgydave

Joined Jun 22, 2012
8,681
Your circuit is ok,but the amplifier needs more voltage to work correctly, you may find your amplifier doesn't give much volume at 3.7v.
 

Kermit2

Joined Feb 5, 2010
4,163
Run two 3.7 volt batteries in series for 7.2 volts then add the 5 volt regulator. You can get more of the energy out of the batteries this way. Use a low drop out regulator. They will be called LDO voltage regulators
 

wayneh

Joined Sep 9, 2010
16,162
Do you have a separate, dedicated charger for that battery type, or do you want to build something? If you want to build, I would suggest you choose 4 AA Ni-cad batteries or even the SLA I mentioned earlier. They are much easier to charge properly with simple, do-it-yourself circuits. For a beginner such as yourself, a Li-ion charger is a "big" project that requires a special IC designed for charging Li-ion cells.
 
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