Looking all over my house for a charger if find a charger with 0.3A-1A or 0.2A is there any difference or damage?

Thread Starter

lse123

Joined Oct 17, 2006
101
I have these PC speakers. The Picture below was connected to a PC but has gone to the recycling... power cord was connected to the rear of the Sony PC same side as the audio cord

P/ V = I ==>

I = 3 W / 12 V = 1 / 4 A = 0.25A

DC 12V 0.25A
I am looking all over my house for a charger,
Q
If I find a charger with 0.3A-1A or 0.2A is there any difference or damage...?

s-l1600a.jpg
 

Ya’akov

Joined Jan 27, 2019
9,143
First, a clarification: you are looking for a power supply. A charger has circuitry to charge batteries. There power supplies are also sometimes called “AC adapters” for legacy reasons.

Second, the “RATED INPUT POWER” of 3W is referring to the audio signal being fed to the speaker, not the DC power being fed to the amplifier in the other speakers housing.

A reasonable guess at the required power is ≤500mA. This would provide 6W of power which should, when power requirements and associated losses are considered, provide more than enough headroom for peak demand.

If the supply is rated to provide less it could be a problem, if it’s rated for more it’s of no importance. Ohm’s Law will show you that a load determines the current at a given voltage, so the two critical parameters are the proper voltage and sufficient current.
 

MrChips

Joined Oct 2, 2009
30,795
PC speakers do not require exact voltage and current specifications.
Wall power adapters (transformer type) will output voltages higher than what is printed on the adapter. If the PC speaker needs 12VDC then any adapter from 7 to 12VDC would be fine.

Your PC speaker needs 12VDC @ 0.25A. The speaker will only take what it needs. There is no harm with using 500mA or 1A adapter.

It is critical to check the polarity of the plug. The SONY PCVA-SP4 requires the centre pin to be positive.

You can often find a suitable power adapter at second hand stores for very low prices.
 

Thread Starter

lse123

Joined Oct 17, 2006
101
Hello, thank you for your support and advice....

After searching around the house, I found two Power Supplies:
// what you recommend: ....?

=1=

20240131_191116.jpg

=2=

20240131_191509.jpg
 

MrChips

Joined Oct 2, 2009
30,795
You don't need 2A but it would still work. Go with the 800mA PSU.
Make sure that whatever you use, check the centre pin polarity with a DMM.
 

Thread Starter

lse123

Joined Oct 17, 2006
101
SO, DO YOU MEAN TO GO WITH THE 1-ST PICTURE? Correct?
Polarity on the picture of 1-st, choose the top-left in the switch changing polarity...? correct?
 

Jon Chandler

Joined Jun 12, 2008
1,048
I would suggest NOT USING the black power supply. It appears to be one of the "battery eliminator" "universal" power supplies, and the shape and vent holes strongly suggest it's a linear supply with a large transformer. These tend to be unregulated, depending on the load drawing enough current to bring the voltage to roughly the claimed voltage.

The white supply appears to be a switch mode supply, which are almost always regulated with the output voltage being what's claimed.
 

MrChips

Joined Oct 2, 2009
30,795
I would suggest NOT USING the black power supply. It appears to be one of the "battery eliminator" "universal" power supplies, and the shape and vent holes strongly suggest it's a linear supply with a large transformer. These tend to be unregulated, depending on the load drawing enough current to bring the voltage to roughly the claimed voltage.

The white supply appears to be a switch mode supply, which are almost always regulated with the output voltage being what's claimed.
I beg to disagree. I would trust a transformer driven linear supply over a SMPS (switch mode power supply) simply because a transformer supply has fewer components that can go wrong (transformer, bridge rectifier, and smoothing capacitor).
 

Thread Starter

lse123

Joined Oct 17, 2006
101
Hello,
MrChips
you say:
"And does the power supply connector mate with that of the PC speaker?"

as the picture shows:
green arrows==black adapter
red arrows==sony speaker cable that the left red arrow shows the plug goes to the rear of Sony PC...

NONE Fits in the Speaker from black power supply multi-use fuse capability,
If I go to a local electronics shop --- may they help me find a solution?

20240201_070154.jpg
 

MrChips

Joined Oct 2, 2009
30,795
SONY PCVA-SP4 requires a plug that properly mates with its power jack.
Usually, I would just cut off the plug and wire a plug that fits, making sure that the polarity is correct. (I cut off the old plug with lots of wire to spare in case I have to use it some other place.)

SONY PCVA-SP5 connector.jpg
 

Thread Starter

lse123

Joined Oct 17, 2006
101
Okay
In case operating system, power the speakers with wrong polarity, in other words, inverse than normal polarity, are they gone to get destroyed ...?
 

MrChips

Joined Oct 2, 2009
30,795
Okay
In case operating system, power the speakers with wrong polarity, in other words, inverse than normal polarity, are they gone to get destroyed ...?
Magic smoke released when wrong polarity applied?
I don't know. I usually don't test this and I avoid doing it.
 

Hemi

Joined Mar 17, 2012
30
Does the white power adapter have the same plug as the speakers? If so, hook it up and you should be good to go.

If not, then it looks like the 3rd green arrow from the left will fit the 1st red arrow from the left. Make sure that black powersupply "voltage change switch" is set to 12V (can't tell from the picture what voltage it is currently set at) and center pin +/positive (which it looks like it already is in your picture).
 
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