I've been trying to find a way to power both a bluetooth receiver and amplifier/speakers using the same battery, but I just can't get it to work properly.
When I tried connecting the bluetooth receiver in parallel to the battery, neither it nor the amplifier/speaker part of the system would be powered simultaneously, despite the fact that the receiver must have a small power draw. In series, nothing at all would turn on.
I can see that this is probably not the ideal way to power this system, but I'd like to ask for the advice from people more experienced than I before I conclude there is nothing I can do to solve my problem!
Included is a labeled photo of the whole thing, for clarity.
3.7v ~7000mAh battery, built in charging circuit also boosts voltage to 5v for charging phones
Bluetooth receiver had its own tiny battery beforehand, also rated at 3.7v
Amp board needs 5v (so works fine plugged into the charging/boost circuit of the battery)
Amp board gets its signal from a 3.5mm jack, which I hope to be able to plug into aforementioned bluetooth receiver
SpikeSmall:
I've been trying to find a way to power both a bluetooth receiver and amplifier/speakers using the same battery, but I just can't get it to work properly.
In series, nothing at all would turn on.
Never do this, its possible to cause damage this way, components are never designed for this.
Connected in parallel neither component should have any problem unless the power source is being
overloaded... I suspect your amplifier is pulling too much current?
Anyway you haven't wired it right, each device should have its supply wires going back to the battery, not
daisy-chained - that will mean each device imposes noise and voltage drop on the next one in the chain.
Thank you, that was very helpful. I had been experiencing some noise so that must explain it.
What do you mean by "this"? Connecting these sorts of components in parallel? Connecting these sorts of components in series? Powering them with the same battery?
You are still risk getting noise if you connect speaker/amplifier to any digital logic, what constitutes
clean DC power for audio circuitry and for digital circuitry are very different. Wiring each
direct to the battery terminals greatly reduces the noise pollution from one device to the other,
but won't eliminate it all. Adding extra decoupling (large value electrolytics like 470uF and up)
to the audio circuitry may help
The usual strategy is to add filtering in stages to the power, with more sensitive circuitry after
more filtering stages, typically a linear voltage regulator or an LC or RC filter would count
as a filtering stage.