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Switch between parallel charge and series load

Rupertrealbear

Mar 31, 2021
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Hi there.
I like - but am terrified of - electrical circuits. I drew up a project to provide a 24v battery power supply to my little Nobo hifi 50W amplifier (I just feel that the cell power is less "noisy" for when it all gets louder).
I got a couple of 12V 9Ah batteries along with a couple of 12V 1500mA.(13.6V 1.5A) chargers to leave in a dual socket 240V panel so that I could leave everything connected to something and change between charging the batteries and using them [in series] with the minimum disruption. Obviously, I would switch off the 240V supply completely before using the amplifier. Also [obviously], the batteries would need to be recharged isolated from each other.
After much thought I came up with the use of a 6PDT 10A 125V toggle switch in a circuit a made into the attached PDF "Battery Charger Switch"
Do any of you marvellous people have an opinion on whether this design should work and how can I put some kind of LED indicating the flow of 24V? (I realise that the amplifier coming on says it all, but the charging part of it already gets lit up like something out of Star Trek)
I do hope I'm not asking questions that any moron could find out by trawling the forums - I am in awe of those morons.
Hope you can help.
Many thanks
RupertrealbearBattery Charger Switch.png
 

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WHONOES

May 20, 2017
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Why do you feel that you have to go to these lengths?
 

Rupertrealbear

Mar 31, 2021
9
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Why do you feel that you have to go to these lengths?
Hi.
Yes, I could just use a 24v power supply . . .
Like I said, I want the purity of cell power for doubling the usual voltage going to my hi fi amp. I have heard a humming, turning up the power and volume on amps, in the past, which I took to be some unavoidable noise that you won't hear over the [greatly] amplified sound anyway.
This project is a way to save disconnecting and reconnecting things on a regular basis. Connectors can wear out.
 

Harald Kapp

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If your chargers are electrically isolated from each other, this setup is much more simple:
upload_2021-4-1_18-49-50.png
 

WHONOES

May 20, 2017
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If you are going to invest in a charger, I think you may be better off investing in a decent regulated power supply as it would be a lot less trouble.
Hi.
Yes, I could just use a 24v power supply . . .
Like I said, I want the purity of cell power for doubling the usual voltage going to my hi fi amp. I have heard a humming, turning up the power and volume on amps, in the past, which I took to be some unavoidable noise that you won't hear over the [greatly] amplified sound anyway.
This project is a way to save disconnecting and reconnecting things on a regular basis. Connectors can wear out.
A properly regulated power supply should be devoid of hum. You would then be able to then leave it permanently connected. The hum could be coming from your signal source.
 

Harald Kapp

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If the hum comes from the connection between amplifier and signal source, stray currents between the different ground systems of amp and source may cause such an issue as hinted at by @WHONOES . A filter between source and amp can eliminate this kind of hum (typically recognizable by its 50 Hz or 60 Hz mains frequency component). Such filters are available in HiFi stores or as audio filters for cars (I know, there's no mains in a car, but the same effect can be present die to long wires).
 

Rupertrealbear

Mar 31, 2021
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If your chargers are electrically isolated from each other, this setup is much more simple:
View attachment 51454
Thank you for that. I did suspect there was a simpler design - leaving the negative leads of the chargers connected (my holistic sense of circuits is too poor, I guess)

If you are going to invest in a charger, I think you may be better off investing in a decent regulated power supply as it would be a lot less trouble.

A properly regulated power supply should be devoid of hum. You would then be able to then leave it permanently connected. The hum could be coming from your signal source.
Thank you, I will look into that!

If the hum comes from the connection between amplifier and signal source, stray currents between the different ground systems of amp and source may cause such an issue as hinted at by @WHONOES . A filter between source and amp can eliminate this kind of hum (typically recognizable by its 50 Hz or 60 Hz mains frequency component). Such filters are available in HiFi stores or as audio filters for cars (I know, there's no mains in a car, but the same effect can be present die to long wires).
Thank you for this also. I will see what is out there in the way of filters
 
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