I have just “repaired” my cd player. It came with a an internal transformer which switched either 120v ac or 240v ac to 9 volt dc internally. (I imagine it is 9 volts DC because it also will take 6 1.5v C batteries at the back) I was using it in a room wired for 120v. One day my landlady had the electricians change over to 220 volts for this space and as I turned on the radio, without knowing of the change, I heard and smelt strange things.
Since then, it has worked (set to 220v) after a fashion with a strange humming noise. Finally, the other day, it quit altogether. What I did today was take out two leads (positive and negative) from the battery area and connect it to one of those small transformers that plugs into 220v AC and sends out DC. I have two available at home. One gives 6.5volts and the other 12volts. Both work. And, the hum is gone. (Guess something had fried the AC circuit in the original internal transformer).
My question is, being a 9 volt cd player, will the use of the transformer which is supplying 12 volts burn the player out? In the past, I have slightly overvolted various DC devices with no harm. It also works on the 6.5 volt transformer.
Quick answer: It might work. The difference between the required voltage and the supplied voltage will likely be wasted as heat via regulators. If this is too much heat, things can get smokey and melty. A cd player doesn’t draw much current so you might be ok.
Better answer: If you want to be safe, get the proper ac adapter. First, determine the device’s actual DC voltage requirement. Either look at the spec on the factory adapter or it will often say on the cd player itself.
Are we talking about a Discman-type single disc portable player? I thought these usually take two AA batteries.
Not a portable player. asks 9 volts in batteries (6 X 1.5v type C). Only cost $30 in the usa. it’s a Coby. I like the sound. So, that’s why I’m willing to just chance it with what I have; don’t want to invest anything in it.
Ok, I just read your OP more carefully and see I misunderstood the question.
Why don’t you just use the 6.5v adapter at the battery terminals? Like you say, that is nominally what the 4 batteries would source and you don’t risk meltiness like with the 12v supply.
Really difficult to understand how a landlord can change from 110 to 220 without ample notification. I’d be looking at her to replace/reimburse the player.
And I can’t picture another cd player that has both a dual voltage (with switch) internal transformer AND takes disposable batteries. ETA: Does this have speakers like a boombox?
From the sound of things, the CD player survived twice its normal voltage (except for the electrolytic filter capacitors in the power supply, explaining the sound/smell and hum), so it might work off of 12 volts since it appears that it has at least some internal regulation (which is needed anyway if you are running from an AC supply because there will be some ripple). Although if the manufacturer was cheap, they might have used 10 volt capacitors instead of 16 volts, which could lead to more pops and outright failure. The only problem with 6.5 volts might be a limited volume before clipping, but if that isn’t a problem it is probably safer to use unless you can examine the internal circuitry.
multivoltage adapters exist for AC (110/220 AC in) which give 3, 4.5, 6, 7.5, 9 and 12 VDC switchable outputs ranging with 0.3A to 0.5A current. they are inexpensive.
you could try to see if it is designed to work down to the 6.5 V you have, some battery devices allow a voltage range down from fresh batteries.
Well as I said, I don’t really want to invest any money in it; the choice was fix it or buy a new one. The only question I had was if it would handle a 12v DC power supply as it appears to be a 9volt setup or DC. I guess I’ll go with the 6 volt DC transformer… (measured 6.5v on my multimeter)
One other thing is to look for a voltage regulator in the original power supply. Most power supplies produce a higher than needed voltage and then regulate it down. A voltage regulator has 3 legs, plus voltage in, ground, and plus out and often a hefty heat sink. The plus in will be connected to the DC making diodes, and plus out to the device itself. Connect the 12 volt supply to the plus in and negative. You could also use a resistor to drop the 12 volts.
I’m very curious about this. Whichever country you live in presumably has a standard voltage for household supply and appliances. Under what circumstance or for what reason would a homeowner decide that the sockets in a certain room will have a different voltage?
I rent a teaching space in the house of a woman in my pueblo (Spain). In that part of the house, the current was at 120v. In her house proper, there was 220v. Which is the norm in the country. 120v was the old system, many moons ago.
This situation lasted for years, until one day I came to work and turned on my CD player without knowing that that very day she had “upgraded” the entire house to 220v.
Upgrading is done by calling in the electrician to do some rewiring.
I don’t know much about this sort of thing, but I can tell you I have been using a 12v power plug for my 9v computer speakers because the original 9v one broke. Been using it for 6 months now and have not had any damage. This is DC btw. Hope that is of somewhat relevance
I’m not getting the repair scenario or the effort expended. Name brand portable and component CD players in perfect shape can be had at many thrifts for $5-$15.
After reading the thread, I just keep thinking back to this post as the answer. Bold added by me:
If that’s all it’s worth, new, just hook up the 12 volts, since you said you tried it and it worked. It’s not worth spending a dime on to try to repair properly. If it’s too much voltage, it’ll die after a short time, so you spend $30 and get a new one. If it’s not too much, it’ll last a while and you’re good. I wouldn’t waste any time, money, or effort trying anything more than that. It’s just too cheap a player to be worth the bother.
